1 /* Functions related to invoking -*- C++ -*- methods and overloaded functions. 2 Copyright (C) 1987-2018 Free Software Foundation, Inc. 3 Contributed by Michael Tiemann (tiemann@cygnus.com) and 4 modified by Brendan Kehoe (brendan@cygnus.com). 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 3, or (at your option) 11 any later version. 12 13 GCC is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 23 /* High-level class interface. */ 24 25 #include "config.h" 26 #include "system.h" 27 #include "coretypes.h" 28 #include "target.h" 29 #include "cp-tree.h" 30 #include "timevar.h" 31 #include "stringpool.h" 32 #include "cgraph.h" 33 #include "stor-layout.h" 34 #include "trans-mem.h" 35 #include "flags.h" 36 #include "toplev.h" 37 #include "intl.h" 38 #include "convert.h" 39 #include "langhooks.h" 40 #include "c-family/c-objc.h" 41 #include "internal-fn.h" 42 #include "stringpool.h" 43 #include "attribs.h" 44 45 /* The various kinds of conversion. */ 46 47 enum conversion_kind { 48 ck_identity, 49 ck_lvalue, 50 ck_fnptr, 51 ck_qual, 52 ck_std, 53 ck_ptr, 54 ck_pmem, 55 ck_base, 56 ck_ref_bind, 57 ck_user, 58 ck_ambig, 59 ck_list, 60 ck_aggr, 61 ck_rvalue 62 }; 63 64 /* The rank of the conversion. Order of the enumerals matters; better 65 conversions should come earlier in the list. */ 66 67 enum conversion_rank { 68 cr_identity, 69 cr_exact, 70 cr_promotion, 71 cr_std, 72 cr_pbool, 73 cr_user, 74 cr_ellipsis, 75 cr_bad 76 }; 77 78 /* An implicit conversion sequence, in the sense of [over.best.ics]. 79 The first conversion to be performed is at the end of the chain. 80 That conversion is always a cr_identity conversion. */ 81 82 struct conversion { 83 /* The kind of conversion represented by this step. */ 84 conversion_kind kind; 85 /* The rank of this conversion. */ 86 conversion_rank rank; 87 BOOL_BITFIELD user_conv_p : 1; 88 BOOL_BITFIELD ellipsis_p : 1; 89 BOOL_BITFIELD this_p : 1; 90 /* True if this conversion would be permitted with a bending of 91 language standards, e.g. disregarding pointer qualifiers or 92 converting integers to pointers. */ 93 BOOL_BITFIELD bad_p : 1; 94 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a 95 temporary should be created to hold the result of the 96 conversion. If KIND is ck_ambig, true if the context is 97 copy-initialization. */ 98 BOOL_BITFIELD need_temporary_p : 1; 99 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion 100 from a pointer-to-derived to pointer-to-base is being performed. */ 101 BOOL_BITFIELD base_p : 1; 102 /* If KIND is ck_ref_bind, true when either an lvalue reference is 103 being bound to an lvalue expression or an rvalue reference is 104 being bound to an rvalue expression. If KIND is ck_rvalue, 105 true when we are treating an lvalue as an rvalue (12.8p33). If 106 KIND is ck_base, always false. If ck_identity, we will be 107 binding a reference directly or decaying to a pointer. */ 108 BOOL_BITFIELD rvaluedness_matches_p: 1; 109 BOOL_BITFIELD check_narrowing: 1; 110 /* The type of the expression resulting from the conversion. */ 111 tree type; 112 union { 113 /* The next conversion in the chain. Since the conversions are 114 arranged from outermost to innermost, the NEXT conversion will 115 actually be performed before this conversion. This variant is 116 used only when KIND is neither ck_identity, ck_ambig nor 117 ck_list. Please use the next_conversion function instead 118 of using this field directly. */ 119 conversion *next; 120 /* The expression at the beginning of the conversion chain. This 121 variant is used only if KIND is ck_identity or ck_ambig. */ 122 tree expr; 123 /* The array of conversions for an initializer_list, so this 124 variant is used only when KIN D is ck_list. */ 125 conversion **list; 126 } u; 127 /* The function candidate corresponding to this conversion 128 sequence. This field is only used if KIND is ck_user. */ 129 struct z_candidate *cand; 130 }; 131 132 #define CONVERSION_RANK(NODE) \ 133 ((NODE)->bad_p ? cr_bad \ 134 : (NODE)->ellipsis_p ? cr_ellipsis \ 135 : (NODE)->user_conv_p ? cr_user \ 136 : (NODE)->rank) 137 138 #define BAD_CONVERSION_RANK(NODE) \ 139 ((NODE)->ellipsis_p ? cr_ellipsis \ 140 : (NODE)->user_conv_p ? cr_user \ 141 : (NODE)->rank) 142 143 static struct obstack conversion_obstack; 144 static bool conversion_obstack_initialized; 145 struct rejection_reason; 146 147 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t); 148 static int equal_functions (tree, tree); 149 static int joust (struct z_candidate *, struct z_candidate *, bool, 150 tsubst_flags_t); 151 static int compare_ics (conversion *, conversion *); 152 static void maybe_warn_class_memaccess (location_t, tree, 153 const vec<tree, va_gc> *); 154 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t); 155 #define convert_like(CONV, EXPR, COMPLAIN) \ 156 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, \ 157 /*issue_conversion_warnings=*/true, \ 158 /*c_cast_p=*/false, (COMPLAIN)) 159 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \ 160 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), \ 161 /*issue_conversion_warnings=*/true, \ 162 /*c_cast_p=*/false, (COMPLAIN)) 163 static tree convert_like_real (conversion *, tree, tree, int, bool, 164 bool, tsubst_flags_t); 165 static void op_error (location_t, enum tree_code, enum tree_code, tree, 166 tree, tree, bool); 167 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int, 168 tsubst_flags_t); 169 static void print_z_candidate (location_t, const char *, struct z_candidate *); 170 static void print_z_candidates (location_t, struct z_candidate *); 171 static tree build_this (tree); 172 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *); 173 static bool any_strictly_viable (struct z_candidate *); 174 static struct z_candidate *add_template_candidate 175 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 176 tree, tree, tree, int, unification_kind_t, tsubst_flags_t); 177 static struct z_candidate *add_template_candidate_real 178 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *, 179 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t); 180 static void add_builtin_candidates 181 (struct z_candidate **, enum tree_code, enum tree_code, 182 tree, tree *, int, tsubst_flags_t); 183 static void add_builtin_candidate 184 (struct z_candidate **, enum tree_code, enum tree_code, 185 tree, tree, tree, tree *, tree *, int, tsubst_flags_t); 186 static bool is_complete (tree); 187 static void build_builtin_candidate 188 (struct z_candidate **, tree, tree, tree, tree *, tree *, 189 int, tsubst_flags_t); 190 static struct z_candidate *add_conv_candidate 191 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, tree, 192 tree, tsubst_flags_t); 193 static struct z_candidate *add_function_candidate 194 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree, 195 tree, int, tsubst_flags_t); 196 static conversion *implicit_conversion (tree, tree, tree, bool, int, 197 tsubst_flags_t); 198 static conversion *reference_binding (tree, tree, tree, bool, int, 199 tsubst_flags_t); 200 static conversion *build_conv (conversion_kind, tree, conversion *); 201 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t); 202 static conversion *next_conversion (conversion *); 203 static bool is_subseq (conversion *, conversion *); 204 static conversion *maybe_handle_ref_bind (conversion **); 205 static void maybe_handle_implicit_object (conversion **); 206 static struct z_candidate *add_candidate 207 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t, 208 conversion **, tree, tree, int, struct rejection_reason *, int); 209 static tree source_type (conversion *); 210 static void add_warning (struct z_candidate *, struct z_candidate *); 211 static bool reference_compatible_p (tree, tree); 212 static conversion *direct_reference_binding (tree, conversion *); 213 static bool promoted_arithmetic_type_p (tree); 214 static conversion *conditional_conversion (tree, tree, tsubst_flags_t); 215 static char *name_as_c_string (tree, tree, bool *); 216 static tree prep_operand (tree); 217 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree, 218 bool, tree, tree, int, struct z_candidate **, 219 tsubst_flags_t); 220 static conversion *merge_conversion_sequences (conversion *, conversion *); 221 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t); 222 223 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE. 224 NAME can take many forms... */ 225 226 bool 227 check_dtor_name (tree basetype, tree name) 228 { 229 /* Just accept something we've already complained about. */ 230 if (name == error_mark_node) 231 return true; 232 233 if (TREE_CODE (name) == TYPE_DECL) 234 name = TREE_TYPE (name); 235 else if (TYPE_P (name)) 236 /* OK */; 237 else if (identifier_p (name)) 238 { 239 if ((MAYBE_CLASS_TYPE_P (basetype) 240 || TREE_CODE (basetype) == ENUMERAL_TYPE) 241 && name == constructor_name (basetype)) 242 return true; 243 else 244 name = get_type_value (name); 245 } 246 else 247 { 248 /* In the case of: 249 250 template <class T> struct S { ~S(); }; 251 int i; 252 i.~S(); 253 254 NAME will be a class template. */ 255 gcc_assert (DECL_CLASS_TEMPLATE_P (name)); 256 return false; 257 } 258 259 if (!name || name == error_mark_node) 260 return false; 261 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name)); 262 } 263 264 /* We want the address of a function or method. We avoid creating a 265 pointer-to-member function. */ 266 267 tree 268 build_addr_func (tree function, tsubst_flags_t complain) 269 { 270 tree type = TREE_TYPE (function); 271 272 /* We have to do these by hand to avoid real pointer to member 273 functions. */ 274 if (TREE_CODE (type) == METHOD_TYPE) 275 { 276 if (TREE_CODE (function) == OFFSET_REF) 277 { 278 tree object = build_address (TREE_OPERAND (function, 0)); 279 return get_member_function_from_ptrfunc (&object, 280 TREE_OPERAND (function, 1), 281 complain); 282 } 283 function = build_address (function); 284 } 285 else 286 function = decay_conversion (function, complain, /*reject_builtin=*/false); 287 288 return function; 289 } 290 291 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or 292 POINTER_TYPE to those. Note, pointer to member function types 293 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are 294 two variants. build_call_a is the primitive taking an array of 295 arguments, while build_call_n is a wrapper that handles varargs. */ 296 297 tree 298 build_call_n (tree function, int n, ...) 299 { 300 if (n == 0) 301 return build_call_a (function, 0, NULL); 302 else 303 { 304 tree *argarray = XALLOCAVEC (tree, n); 305 va_list ap; 306 int i; 307 308 va_start (ap, n); 309 for (i = 0; i < n; i++) 310 argarray[i] = va_arg (ap, tree); 311 va_end (ap); 312 return build_call_a (function, n, argarray); 313 } 314 } 315 316 /* Update various flags in cfun and the call itself based on what is being 317 called. Split out of build_call_a so that bot_manip can use it too. */ 318 319 void 320 set_flags_from_callee (tree call) 321 { 322 bool nothrow; 323 tree decl = get_callee_fndecl (call); 324 325 /* We check both the decl and the type; a function may be known not to 326 throw without being declared throw(). */ 327 nothrow = decl && TREE_NOTHROW (decl); 328 if (CALL_EXPR_FN (call)) 329 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call)))); 330 else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW) 331 nothrow = true; 332 333 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain) 334 cp_function_chain->can_throw = 1; 335 336 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain) 337 current_function_returns_abnormally = 1; 338 339 TREE_NOTHROW (call) = nothrow; 340 } 341 342 tree 343 build_call_a (tree function, int n, tree *argarray) 344 { 345 tree decl; 346 tree result_type; 347 tree fntype; 348 int i; 349 350 function = build_addr_func (function, tf_warning_or_error); 351 352 gcc_assert (TYPE_PTR_P (TREE_TYPE (function))); 353 fntype = TREE_TYPE (TREE_TYPE (function)); 354 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE 355 || TREE_CODE (fntype) == METHOD_TYPE); 356 result_type = TREE_TYPE (fntype); 357 /* An rvalue has no cv-qualifiers. */ 358 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type)) 359 result_type = cv_unqualified (result_type); 360 361 function = build_call_array_loc (input_location, 362 result_type, function, n, argarray); 363 set_flags_from_callee (function); 364 365 decl = get_callee_fndecl (function); 366 367 if (decl && !TREE_USED (decl)) 368 { 369 /* We invoke build_call directly for several library 370 functions. These may have been declared normally if 371 we're building libgcc, so we can't just check 372 DECL_ARTIFICIAL. */ 373 gcc_assert (DECL_ARTIFICIAL (decl) 374 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)), 375 "__", 2)); 376 mark_used (decl); 377 } 378 379 require_complete_eh_spec_types (fntype, decl); 380 381 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl)); 382 383 /* Don't pass empty class objects by value. This is useful 384 for tags in STL, which are used to control overload resolution. 385 We don't need to handle other cases of copying empty classes. */ 386 if (! decl || ! DECL_BUILT_IN (decl)) 387 for (i = 0; i < n; i++) 388 { 389 tree arg = CALL_EXPR_ARG (function, i); 390 if (is_empty_class (TREE_TYPE (arg)) 391 && ! TREE_ADDRESSABLE (TREE_TYPE (arg))) 392 { 393 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg)); 394 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t); 395 CALL_EXPR_ARG (function, i) = arg; 396 } 397 } 398 399 return function; 400 } 401 402 /* New overloading code. */ 403 404 struct z_candidate; 405 406 struct candidate_warning { 407 z_candidate *loser; 408 candidate_warning *next; 409 }; 410 411 /* Information for providing diagnostics about why overloading failed. */ 412 413 enum rejection_reason_code { 414 rr_none, 415 rr_arity, 416 rr_explicit_conversion, 417 rr_template_conversion, 418 rr_arg_conversion, 419 rr_bad_arg_conversion, 420 rr_template_unification, 421 rr_invalid_copy, 422 rr_inherited_ctor, 423 rr_constraint_failure 424 }; 425 426 struct conversion_info { 427 /* The index of the argument, 0-based. */ 428 int n_arg; 429 /* The actual argument or its type. */ 430 tree from; 431 /* The type of the parameter. */ 432 tree to_type; 433 }; 434 435 struct rejection_reason { 436 enum rejection_reason_code code; 437 union { 438 /* Information about an arity mismatch. */ 439 struct { 440 /* The expected number of arguments. */ 441 int expected; 442 /* The actual number of arguments in the call. */ 443 int actual; 444 /* Whether the call was a varargs call. */ 445 bool call_varargs_p; 446 } arity; 447 /* Information about an argument conversion mismatch. */ 448 struct conversion_info conversion; 449 /* Same, but for bad argument conversions. */ 450 struct conversion_info bad_conversion; 451 /* Information about template unification failures. These are the 452 parameters passed to fn_type_unification. */ 453 struct { 454 tree tmpl; 455 tree explicit_targs; 456 int num_targs; 457 const tree *args; 458 unsigned int nargs; 459 tree return_type; 460 unification_kind_t strict; 461 int flags; 462 } template_unification; 463 /* Information about template instantiation failures. These are the 464 parameters passed to instantiate_template. */ 465 struct { 466 tree tmpl; 467 tree targs; 468 } template_instantiation; 469 } u; 470 }; 471 472 struct z_candidate { 473 /* The FUNCTION_DECL that will be called if this candidate is 474 selected by overload resolution. */ 475 tree fn; 476 /* If not NULL_TREE, the first argument to use when calling this 477 function. */ 478 tree first_arg; 479 /* The rest of the arguments to use when calling this function. If 480 there are no further arguments this may be NULL or it may be an 481 empty vector. */ 482 const vec<tree, va_gc> *args; 483 /* The implicit conversion sequences for each of the arguments to 484 FN. */ 485 conversion **convs; 486 /* The number of implicit conversion sequences. */ 487 size_t num_convs; 488 /* If FN is a user-defined conversion, the standard conversion 489 sequence from the type returned by FN to the desired destination 490 type. */ 491 conversion *second_conv; 492 struct rejection_reason *reason; 493 /* If FN is a member function, the binfo indicating the path used to 494 qualify the name of FN at the call site. This path is used to 495 determine whether or not FN is accessible if it is selected by 496 overload resolution. The DECL_CONTEXT of FN will always be a 497 (possibly improper) base of this binfo. */ 498 tree access_path; 499 /* If FN is a non-static member function, the binfo indicating the 500 subobject to which the `this' pointer should be converted if FN 501 is selected by overload resolution. The type pointed to by 502 the `this' pointer must correspond to the most derived class 503 indicated by the CONVERSION_PATH. */ 504 tree conversion_path; 505 tree template_decl; 506 tree explicit_targs; 507 candidate_warning *warnings; 508 z_candidate *next; 509 int viable; 510 511 /* The flags active in add_candidate. */ 512 int flags; 513 }; 514 515 /* Returns true iff T is a null pointer constant in the sense of 516 [conv.ptr]. */ 517 518 bool 519 null_ptr_cst_p (tree t) 520 { 521 tree type = TREE_TYPE (t); 522 523 /* [conv.ptr] 524 525 A null pointer constant is an integral constant expression 526 (_expr.const_) rvalue of integer type that evaluates to zero or 527 an rvalue of type std::nullptr_t. */ 528 if (NULLPTR_TYPE_P (type)) 529 return true; 530 531 if (cxx_dialect >= cxx11) 532 { 533 STRIP_ANY_LOCATION_WRAPPER (t); 534 535 /* Core issue 903 says only literal 0 is a null pointer constant. */ 536 if (TREE_CODE (type) == INTEGER_TYPE 537 && !char_type_p (type) 538 && TREE_CODE (t) == INTEGER_CST 539 && integer_zerop (t) 540 && !TREE_OVERFLOW (t)) 541 return true; 542 } 543 else if (CP_INTEGRAL_TYPE_P (type)) 544 { 545 t = fold_non_dependent_expr (t); 546 STRIP_NOPS (t); 547 if (integer_zerop (t) && !TREE_OVERFLOW (t)) 548 return true; 549 } 550 551 return false; 552 } 553 554 /* Returns true iff T is a null member pointer value (4.11). */ 555 556 bool 557 null_member_pointer_value_p (tree t) 558 { 559 tree type = TREE_TYPE (t); 560 if (!type) 561 return false; 562 else if (TYPE_PTRMEMFUNC_P (type)) 563 return (TREE_CODE (t) == CONSTRUCTOR 564 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value)); 565 else if (TYPE_PTRDATAMEM_P (type)) 566 return integer_all_onesp (t); 567 else 568 return false; 569 } 570 571 /* Returns nonzero if PARMLIST consists of only default parms, 572 ellipsis, and/or undeduced parameter packs. */ 573 574 bool 575 sufficient_parms_p (const_tree parmlist) 576 { 577 for (; parmlist && parmlist != void_list_node; 578 parmlist = TREE_CHAIN (parmlist)) 579 if (!TREE_PURPOSE (parmlist) 580 && !PACK_EXPANSION_P (TREE_VALUE (parmlist))) 581 return false; 582 return true; 583 } 584 585 /* Allocate N bytes of memory from the conversion obstack. The memory 586 is zeroed before being returned. */ 587 588 static void * 589 conversion_obstack_alloc (size_t n) 590 { 591 void *p; 592 if (!conversion_obstack_initialized) 593 { 594 gcc_obstack_init (&conversion_obstack); 595 conversion_obstack_initialized = true; 596 } 597 p = obstack_alloc (&conversion_obstack, n); 598 memset (p, 0, n); 599 return p; 600 } 601 602 /* Allocate rejection reasons. */ 603 604 static struct rejection_reason * 605 alloc_rejection (enum rejection_reason_code code) 606 { 607 struct rejection_reason *p; 608 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p); 609 p->code = code; 610 return p; 611 } 612 613 static struct rejection_reason * 614 arity_rejection (tree first_arg, int expected, int actual) 615 { 616 struct rejection_reason *r = alloc_rejection (rr_arity); 617 int adjust = first_arg != NULL_TREE; 618 r->u.arity.expected = expected - adjust; 619 r->u.arity.actual = actual - adjust; 620 return r; 621 } 622 623 static struct rejection_reason * 624 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 625 { 626 struct rejection_reason *r = alloc_rejection (rr_arg_conversion); 627 int adjust = first_arg != NULL_TREE; 628 r->u.conversion.n_arg = n_arg - adjust; 629 r->u.conversion.from = from; 630 r->u.conversion.to_type = to; 631 return r; 632 } 633 634 static struct rejection_reason * 635 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to) 636 { 637 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion); 638 int adjust = first_arg != NULL_TREE; 639 r->u.bad_conversion.n_arg = n_arg - adjust; 640 r->u.bad_conversion.from = from; 641 r->u.bad_conversion.to_type = to; 642 return r; 643 } 644 645 static struct rejection_reason * 646 explicit_conversion_rejection (tree from, tree to) 647 { 648 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion); 649 r->u.conversion.n_arg = 0; 650 r->u.conversion.from = from; 651 r->u.conversion.to_type = to; 652 return r; 653 } 654 655 static struct rejection_reason * 656 template_conversion_rejection (tree from, tree to) 657 { 658 struct rejection_reason *r = alloc_rejection (rr_template_conversion); 659 r->u.conversion.n_arg = 0; 660 r->u.conversion.from = from; 661 r->u.conversion.to_type = to; 662 return r; 663 } 664 665 static struct rejection_reason * 666 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs, 667 const tree *args, unsigned int nargs, 668 tree return_type, unification_kind_t strict, 669 int flags) 670 { 671 size_t args_n_bytes = sizeof (*args) * nargs; 672 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes); 673 struct rejection_reason *r = alloc_rejection (rr_template_unification); 674 r->u.template_unification.tmpl = tmpl; 675 r->u.template_unification.explicit_targs = explicit_targs; 676 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs); 677 /* Copy args to our own storage. */ 678 memcpy (args1, args, args_n_bytes); 679 r->u.template_unification.args = args1; 680 r->u.template_unification.nargs = nargs; 681 r->u.template_unification.return_type = return_type; 682 r->u.template_unification.strict = strict; 683 r->u.template_unification.flags = flags; 684 return r; 685 } 686 687 static struct rejection_reason * 688 template_unification_error_rejection (void) 689 { 690 return alloc_rejection (rr_template_unification); 691 } 692 693 static struct rejection_reason * 694 invalid_copy_with_fn_template_rejection (void) 695 { 696 struct rejection_reason *r = alloc_rejection (rr_invalid_copy); 697 return r; 698 } 699 700 static struct rejection_reason * 701 inherited_ctor_rejection (void) 702 { 703 struct rejection_reason *r = alloc_rejection (rr_inherited_ctor); 704 return r; 705 } 706 707 // Build a constraint failure record, saving information into the 708 // template_instantiation field of the rejection. If FN is not a template 709 // declaration, the TMPL member is the FN declaration and TARGS is empty. 710 711 static struct rejection_reason * 712 constraint_failure (tree fn) 713 { 714 struct rejection_reason *r = alloc_rejection (rr_constraint_failure); 715 if (tree ti = DECL_TEMPLATE_INFO (fn)) 716 { 717 r->u.template_instantiation.tmpl = TI_TEMPLATE (ti); 718 r->u.template_instantiation.targs = TI_ARGS (ti); 719 } 720 else 721 { 722 r->u.template_instantiation.tmpl = fn; 723 r->u.template_instantiation.targs = NULL_TREE; 724 } 725 return r; 726 } 727 728 /* Dynamically allocate a conversion. */ 729 730 static conversion * 731 alloc_conversion (conversion_kind kind) 732 { 733 conversion *c; 734 c = (conversion *) conversion_obstack_alloc (sizeof (conversion)); 735 c->kind = kind; 736 return c; 737 } 738 739 /* Make sure that all memory on the conversion obstack has been 740 freed. */ 741 742 void 743 validate_conversion_obstack (void) 744 { 745 if (conversion_obstack_initialized) 746 gcc_assert ((obstack_next_free (&conversion_obstack) 747 == obstack_base (&conversion_obstack))); 748 } 749 750 /* Dynamically allocate an array of N conversions. */ 751 752 static conversion ** 753 alloc_conversions (size_t n) 754 { 755 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *)); 756 } 757 758 static conversion * 759 build_conv (conversion_kind code, tree type, conversion *from) 760 { 761 conversion *t; 762 conversion_rank rank = CONVERSION_RANK (from); 763 764 /* Note that the caller is responsible for filling in t->cand for 765 user-defined conversions. */ 766 t = alloc_conversion (code); 767 t->type = type; 768 t->u.next = from; 769 770 switch (code) 771 { 772 case ck_ptr: 773 case ck_pmem: 774 case ck_base: 775 case ck_std: 776 if (rank < cr_std) 777 rank = cr_std; 778 break; 779 780 case ck_qual: 781 case ck_fnptr: 782 if (rank < cr_exact) 783 rank = cr_exact; 784 break; 785 786 default: 787 break; 788 } 789 t->rank = rank; 790 t->user_conv_p = (code == ck_user || from->user_conv_p); 791 t->bad_p = from->bad_p; 792 t->base_p = false; 793 return t; 794 } 795 796 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 797 specialization of std::initializer_list<T>, if such a conversion is 798 possible. */ 799 800 static conversion * 801 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 802 { 803 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0); 804 unsigned len = CONSTRUCTOR_NELTS (ctor); 805 conversion **subconvs = alloc_conversions (len); 806 conversion *t; 807 unsigned i; 808 tree val; 809 810 /* Within a list-initialization we can have more user-defined 811 conversions. */ 812 flags &= ~LOOKUP_NO_CONVERSION; 813 /* But no narrowing conversions. */ 814 flags |= LOOKUP_NO_NARROWING; 815 816 /* Can't make an array of these types. */ 817 if (TREE_CODE (elttype) == REFERENCE_TYPE 818 || TREE_CODE (elttype) == FUNCTION_TYPE 819 || VOID_TYPE_P (elttype)) 820 return NULL; 821 822 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 823 { 824 conversion *sub 825 = implicit_conversion (elttype, TREE_TYPE (val), val, 826 false, flags, complain); 827 if (sub == NULL) 828 return NULL; 829 830 subconvs[i] = sub; 831 } 832 833 t = alloc_conversion (ck_list); 834 t->type = type; 835 t->u.list = subconvs; 836 t->rank = cr_exact; 837 838 for (i = 0; i < len; ++i) 839 { 840 conversion *sub = subconvs[i]; 841 if (sub->rank > t->rank) 842 t->rank = sub->rank; 843 if (sub->user_conv_p) 844 t->user_conv_p = true; 845 if (sub->bad_p) 846 t->bad_p = true; 847 } 848 849 return t; 850 } 851 852 /* Return the next conversion of the conversion chain (if applicable), 853 or NULL otherwise. Please use this function instead of directly 854 accessing fields of struct conversion. */ 855 856 static conversion * 857 next_conversion (conversion *conv) 858 { 859 if (conv == NULL 860 || conv->kind == ck_identity 861 || conv->kind == ck_ambig 862 || conv->kind == ck_list) 863 return NULL; 864 return conv->u.next; 865 } 866 867 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list, 868 is a valid aggregate initializer for array type ATYPE. */ 869 870 static bool 871 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain) 872 { 873 unsigned i; 874 tree elttype = TREE_TYPE (atype); 875 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i) 876 { 877 tree val = CONSTRUCTOR_ELT (ctor, i)->value; 878 bool ok; 879 if (TREE_CODE (elttype) == ARRAY_TYPE 880 && TREE_CODE (val) == CONSTRUCTOR) 881 ok = can_convert_array (elttype, val, flags, complain); 882 else 883 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags, 884 complain); 885 if (!ok) 886 return false; 887 } 888 return true; 889 } 890 891 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 892 aggregate class, if such a conversion is possible. */ 893 894 static conversion * 895 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 896 { 897 unsigned HOST_WIDE_INT i = 0; 898 conversion *c; 899 tree field = next_initializable_field (TYPE_FIELDS (type)); 900 tree empty_ctor = NULL_TREE; 901 902 /* We already called reshape_init in implicit_conversion. */ 903 904 /* The conversions within the init-list aren't affected by the enclosing 905 context; they're always simple copy-initialization. */ 906 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 907 908 for (; field; field = next_initializable_field (DECL_CHAIN (field))) 909 { 910 tree ftype = TREE_TYPE (field); 911 tree val; 912 bool ok; 913 914 if (i < CONSTRUCTOR_NELTS (ctor)) 915 val = CONSTRUCTOR_ELT (ctor, i)->value; 916 else if (DECL_INITIAL (field)) 917 val = get_nsdmi (field, /*ctor*/false, complain); 918 else if (TREE_CODE (ftype) == REFERENCE_TYPE) 919 /* Value-initialization of reference is ill-formed. */ 920 return NULL; 921 else 922 { 923 if (empty_ctor == NULL_TREE) 924 empty_ctor = build_constructor (init_list_type_node, NULL); 925 val = empty_ctor; 926 } 927 ++i; 928 929 if (TREE_CODE (ftype) == ARRAY_TYPE 930 && TREE_CODE (val) == CONSTRUCTOR) 931 ok = can_convert_array (ftype, val, flags, complain); 932 else 933 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags, 934 complain); 935 936 if (!ok) 937 return NULL; 938 939 if (TREE_CODE (type) == UNION_TYPE) 940 break; 941 } 942 943 if (i < CONSTRUCTOR_NELTS (ctor)) 944 return NULL; 945 946 c = alloc_conversion (ck_aggr); 947 c->type = type; 948 c->rank = cr_exact; 949 c->user_conv_p = true; 950 c->check_narrowing = true; 951 c->u.next = NULL; 952 return c; 953 } 954 955 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an 956 array type, if such a conversion is possible. */ 957 958 static conversion * 959 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain) 960 { 961 conversion *c; 962 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 963 tree elttype = TREE_TYPE (type); 964 unsigned i; 965 tree val; 966 bool bad = false; 967 bool user = false; 968 enum conversion_rank rank = cr_exact; 969 970 /* We might need to propagate the size from the element to the array. */ 971 complete_type (type); 972 973 if (TYPE_DOMAIN (type) 974 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE)) 975 { 976 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type)); 977 if (alen < len) 978 return NULL; 979 } 980 981 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 982 983 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 984 { 985 conversion *sub 986 = implicit_conversion (elttype, TREE_TYPE (val), val, 987 false, flags, complain); 988 if (sub == NULL) 989 return NULL; 990 991 if (sub->rank > rank) 992 rank = sub->rank; 993 if (sub->user_conv_p) 994 user = true; 995 if (sub->bad_p) 996 bad = true; 997 } 998 999 c = alloc_conversion (ck_aggr); 1000 c->type = type; 1001 c->rank = rank; 1002 c->user_conv_p = user; 1003 c->bad_p = bad; 1004 c->u.next = NULL; 1005 return c; 1006 } 1007 1008 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a 1009 complex type, if such a conversion is possible. */ 1010 1011 static conversion * 1012 build_complex_conv (tree type, tree ctor, int flags, 1013 tsubst_flags_t complain) 1014 { 1015 conversion *c; 1016 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor); 1017 tree elttype = TREE_TYPE (type); 1018 unsigned i; 1019 tree val; 1020 bool bad = false; 1021 bool user = false; 1022 enum conversion_rank rank = cr_exact; 1023 1024 if (len != 2) 1025 return NULL; 1026 1027 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING; 1028 1029 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val) 1030 { 1031 conversion *sub 1032 = implicit_conversion (elttype, TREE_TYPE (val), val, 1033 false, flags, complain); 1034 if (sub == NULL) 1035 return NULL; 1036 1037 if (sub->rank > rank) 1038 rank = sub->rank; 1039 if (sub->user_conv_p) 1040 user = true; 1041 if (sub->bad_p) 1042 bad = true; 1043 } 1044 1045 c = alloc_conversion (ck_aggr); 1046 c->type = type; 1047 c->rank = rank; 1048 c->user_conv_p = user; 1049 c->bad_p = bad; 1050 c->u.next = NULL; 1051 return c; 1052 } 1053 1054 /* Build a representation of the identity conversion from EXPR to 1055 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */ 1056 1057 static conversion * 1058 build_identity_conv (tree type, tree expr) 1059 { 1060 conversion *c; 1061 1062 c = alloc_conversion (ck_identity); 1063 c->type = type; 1064 c->u.expr = expr; 1065 1066 return c; 1067 } 1068 1069 /* Converting from EXPR to TYPE was ambiguous in the sense that there 1070 were multiple user-defined conversions to accomplish the job. 1071 Build a conversion that indicates that ambiguity. */ 1072 1073 static conversion * 1074 build_ambiguous_conv (tree type, tree expr) 1075 { 1076 conversion *c; 1077 1078 c = alloc_conversion (ck_ambig); 1079 c->type = type; 1080 c->u.expr = expr; 1081 1082 return c; 1083 } 1084 1085 tree 1086 strip_top_quals (tree t) 1087 { 1088 if (TREE_CODE (t) == ARRAY_TYPE) 1089 return t; 1090 return cp_build_qualified_type (t, 0); 1091 } 1092 1093 /* Returns the standard conversion path (see [conv]) from type FROM to type 1094 TO, if any. For proper handling of null pointer constants, you must 1095 also pass the expression EXPR to convert from. If C_CAST_P is true, 1096 this conversion is coming from a C-style cast. */ 1097 1098 static conversion * 1099 standard_conversion (tree to, tree from, tree expr, bool c_cast_p, 1100 int flags, tsubst_flags_t complain) 1101 { 1102 enum tree_code fcode, tcode; 1103 conversion *conv; 1104 bool fromref = false; 1105 tree qualified_to; 1106 1107 to = non_reference (to); 1108 if (TREE_CODE (from) == REFERENCE_TYPE) 1109 { 1110 fromref = true; 1111 from = TREE_TYPE (from); 1112 } 1113 qualified_to = to; 1114 to = strip_top_quals (to); 1115 from = strip_top_quals (from); 1116 1117 if (expr && type_unknown_p (expr)) 1118 { 1119 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to)) 1120 { 1121 tsubst_flags_t tflags = tf_conv; 1122 expr = instantiate_type (to, expr, tflags); 1123 if (expr == error_mark_node) 1124 return NULL; 1125 from = TREE_TYPE (expr); 1126 } 1127 else if (TREE_CODE (to) == BOOLEAN_TYPE) 1128 { 1129 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */ 1130 expr = resolve_nondeduced_context (expr, complain); 1131 from = TREE_TYPE (expr); 1132 } 1133 } 1134 1135 fcode = TREE_CODE (from); 1136 tcode = TREE_CODE (to); 1137 1138 conv = build_identity_conv (from, expr); 1139 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE) 1140 { 1141 from = type_decays_to (from); 1142 fcode = TREE_CODE (from); 1143 /* Tell convert_like_real that we're using the address. */ 1144 conv->rvaluedness_matches_p = true; 1145 conv = build_conv (ck_lvalue, from, conv); 1146 } 1147 /* Wrapping a ck_rvalue around a class prvalue (as a result of using 1148 obvalue_p) seems odd, since it's already a prvalue, but that's how we 1149 express the copy constructor call required by copy-initialization. */ 1150 else if (fromref || (expr && obvalue_p (expr))) 1151 { 1152 if (expr) 1153 { 1154 tree bitfield_type; 1155 bitfield_type = is_bitfield_expr_with_lowered_type (expr); 1156 if (bitfield_type) 1157 { 1158 from = strip_top_quals (bitfield_type); 1159 fcode = TREE_CODE (from); 1160 } 1161 } 1162 conv = build_conv (ck_rvalue, from, conv); 1163 if (flags & LOOKUP_PREFER_RVALUE) 1164 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */ 1165 conv->rvaluedness_matches_p = true; 1166 } 1167 1168 /* Allow conversion between `__complex__' data types. */ 1169 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE) 1170 { 1171 /* The standard conversion sequence to convert FROM to TO is 1172 the standard conversion sequence to perform componentwise 1173 conversion. */ 1174 conversion *part_conv = standard_conversion 1175 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags, 1176 complain); 1177 1178 if (part_conv) 1179 { 1180 conv = build_conv (part_conv->kind, to, conv); 1181 conv->rank = part_conv->rank; 1182 } 1183 else 1184 conv = NULL; 1185 1186 return conv; 1187 } 1188 1189 if (same_type_p (from, to)) 1190 { 1191 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue) 1192 conv->type = qualified_to; 1193 return conv; 1194 } 1195 1196 /* [conv.ptr] 1197 A null pointer constant can be converted to a pointer type; ... A 1198 null pointer constant of integral type can be converted to an 1199 rvalue of type std::nullptr_t. */ 1200 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to) 1201 || NULLPTR_TYPE_P (to)) 1202 && ((expr && null_ptr_cst_p (expr)) 1203 || NULLPTR_TYPE_P (from))) 1204 conv = build_conv (ck_std, to, conv); 1205 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE) 1206 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE)) 1207 { 1208 /* For backwards brain damage compatibility, allow interconversion of 1209 pointers and integers with a pedwarn. */ 1210 conv = build_conv (ck_std, to, conv); 1211 conv->bad_p = true; 1212 } 1213 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE) 1214 { 1215 /* For backwards brain damage compatibility, allow interconversion of 1216 enums and integers with a pedwarn. */ 1217 conv = build_conv (ck_std, to, conv); 1218 conv->bad_p = true; 1219 } 1220 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE) 1221 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from))) 1222 { 1223 tree to_pointee; 1224 tree from_pointee; 1225 1226 if (tcode == POINTER_TYPE) 1227 { 1228 to_pointee = TREE_TYPE (to); 1229 from_pointee = TREE_TYPE (from); 1230 1231 /* Since this is the target of a pointer, it can't have function 1232 qualifiers, so any TYPE_QUALS must be for attributes const or 1233 noreturn. Strip them. */ 1234 if (TREE_CODE (to_pointee) == FUNCTION_TYPE 1235 && TYPE_QUALS (to_pointee)) 1236 to_pointee = build_qualified_type (to_pointee, TYPE_UNQUALIFIED); 1237 if (TREE_CODE (from_pointee) == FUNCTION_TYPE 1238 && TYPE_QUALS (from_pointee)) 1239 from_pointee = build_qualified_type (from_pointee, TYPE_UNQUALIFIED); 1240 } 1241 else 1242 { 1243 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to); 1244 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from); 1245 } 1246 1247 if (tcode == POINTER_TYPE 1248 && same_type_ignoring_top_level_qualifiers_p (from_pointee, 1249 to_pointee)) 1250 ; 1251 else if (VOID_TYPE_P (to_pointee) 1252 && !TYPE_PTRDATAMEM_P (from) 1253 && TREE_CODE (from_pointee) != FUNCTION_TYPE) 1254 { 1255 tree nfrom = TREE_TYPE (from); 1256 /* Don't try to apply restrict to void. */ 1257 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT; 1258 from_pointee = cp_build_qualified_type (void_type_node, quals); 1259 from = build_pointer_type (from_pointee); 1260 conv = build_conv (ck_ptr, from, conv); 1261 } 1262 else if (TYPE_PTRDATAMEM_P (from)) 1263 { 1264 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from); 1265 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to); 1266 1267 if (same_type_p (fbase, tbase)) 1268 /* No base conversion needed. */; 1269 else if (DERIVED_FROM_P (fbase, tbase) 1270 && (same_type_ignoring_top_level_qualifiers_p 1271 (from_pointee, to_pointee))) 1272 { 1273 from = build_ptrmem_type (tbase, from_pointee); 1274 conv = build_conv (ck_pmem, from, conv); 1275 } 1276 else 1277 return NULL; 1278 } 1279 else if (CLASS_TYPE_P (from_pointee) 1280 && CLASS_TYPE_P (to_pointee) 1281 /* [conv.ptr] 1282 1283 An rvalue of type "pointer to cv D," where D is a 1284 class type, can be converted to an rvalue of type 1285 "pointer to cv B," where B is a base class (clause 1286 _class.derived_) of D. If B is an inaccessible 1287 (clause _class.access_) or ambiguous 1288 (_class.member.lookup_) base class of D, a program 1289 that necessitates this conversion is ill-formed. 1290 Therefore, we use DERIVED_FROM_P, and do not check 1291 access or uniqueness. */ 1292 && DERIVED_FROM_P (to_pointee, from_pointee)) 1293 { 1294 from_pointee 1295 = cp_build_qualified_type (to_pointee, 1296 cp_type_quals (from_pointee)); 1297 from = build_pointer_type (from_pointee); 1298 conv = build_conv (ck_ptr, from, conv); 1299 conv->base_p = true; 1300 } 1301 1302 if (same_type_p (from, to)) 1303 /* OK */; 1304 else if (c_cast_p && comp_ptr_ttypes_const (to, from)) 1305 /* In a C-style cast, we ignore CV-qualification because we 1306 are allowed to perform a static_cast followed by a 1307 const_cast. */ 1308 conv = build_conv (ck_qual, to, conv); 1309 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee)) 1310 conv = build_conv (ck_qual, to, conv); 1311 else if (expr && string_conv_p (to, expr, 0)) 1312 /* converting from string constant to char *. */ 1313 conv = build_conv (ck_qual, to, conv); 1314 else if (fnptr_conv_p (to, from)) 1315 conv = build_conv (ck_fnptr, to, conv); 1316 /* Allow conversions among compatible ObjC pointer types (base 1317 conversions have been already handled above). */ 1318 else if (c_dialect_objc () 1319 && objc_compare_types (to, from, -4, NULL_TREE)) 1320 conv = build_conv (ck_ptr, to, conv); 1321 else if (ptr_reasonably_similar (to_pointee, from_pointee)) 1322 { 1323 conv = build_conv (ck_ptr, to, conv); 1324 conv->bad_p = true; 1325 } 1326 else 1327 return NULL; 1328 1329 from = to; 1330 } 1331 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from)) 1332 { 1333 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from)); 1334 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to)); 1335 tree fbase = class_of_this_parm (fromfn); 1336 tree tbase = class_of_this_parm (tofn); 1337 1338 if (!DERIVED_FROM_P (fbase, tbase)) 1339 return NULL; 1340 1341 tree fstat = static_fn_type (fromfn); 1342 tree tstat = static_fn_type (tofn); 1343 if (same_type_p (tstat, fstat) 1344 || fnptr_conv_p (tstat, fstat)) 1345 /* OK */; 1346 else 1347 return NULL; 1348 1349 if (!same_type_p (fbase, tbase)) 1350 { 1351 from = build_memfn_type (fstat, 1352 tbase, 1353 cp_type_quals (tbase), 1354 type_memfn_rqual (tofn)); 1355 from = build_ptrmemfunc_type (build_pointer_type (from)); 1356 conv = build_conv (ck_pmem, from, conv); 1357 conv->base_p = true; 1358 } 1359 if (fnptr_conv_p (tstat, fstat)) 1360 conv = build_conv (ck_fnptr, to, conv); 1361 } 1362 else if (tcode == BOOLEAN_TYPE) 1363 { 1364 /* [conv.bool] 1365 1366 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer 1367 to member type can be converted to a prvalue of type bool. ... 1368 For direct-initialization (8.5 [dcl.init]), a prvalue of type 1369 std::nullptr_t can be converted to a prvalue of type bool; */ 1370 if (ARITHMETIC_TYPE_P (from) 1371 || UNSCOPED_ENUM_P (from) 1372 || fcode == POINTER_TYPE 1373 || TYPE_PTRMEM_P (from) 1374 || NULLPTR_TYPE_P (from)) 1375 { 1376 conv = build_conv (ck_std, to, conv); 1377 if (fcode == POINTER_TYPE 1378 || TYPE_PTRDATAMEM_P (from) 1379 || (TYPE_PTRMEMFUNC_P (from) 1380 && conv->rank < cr_pbool) 1381 || NULLPTR_TYPE_P (from)) 1382 conv->rank = cr_pbool; 1383 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING)) 1384 conv->bad_p = true; 1385 return conv; 1386 } 1387 1388 return NULL; 1389 } 1390 /* We don't check for ENUMERAL_TYPE here because there are no standard 1391 conversions to enum type. */ 1392 /* As an extension, allow conversion to complex type. */ 1393 else if (ARITHMETIC_TYPE_P (to)) 1394 { 1395 if (! (INTEGRAL_CODE_P (fcode) 1396 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL))) 1397 || SCOPED_ENUM_P (from)) 1398 return NULL; 1399 conv = build_conv (ck_std, to, conv); 1400 1401 /* Give this a better rank if it's a promotion. */ 1402 if (same_type_p (to, type_promotes_to (from)) 1403 && next_conversion (conv)->rank <= cr_promotion) 1404 conv->rank = cr_promotion; 1405 } 1406 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE 1407 && vector_types_convertible_p (from, to, false)) 1408 return build_conv (ck_std, to, conv); 1409 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from) 1410 && is_properly_derived_from (from, to)) 1411 { 1412 if (conv->kind == ck_rvalue) 1413 conv = next_conversion (conv); 1414 conv = build_conv (ck_base, to, conv); 1415 /* The derived-to-base conversion indicates the initialization 1416 of a parameter with base type from an object of a derived 1417 type. A temporary object is created to hold the result of 1418 the conversion unless we're binding directly to a reference. */ 1419 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND); 1420 } 1421 else 1422 return NULL; 1423 1424 if (flags & LOOKUP_NO_NARROWING) 1425 conv->check_narrowing = true; 1426 1427 return conv; 1428 } 1429 1430 /* Returns nonzero if T1 is reference-related to T2. */ 1431 1432 bool 1433 reference_related_p (tree t1, tree t2) 1434 { 1435 if (t1 == error_mark_node || t2 == error_mark_node) 1436 return false; 1437 1438 t1 = TYPE_MAIN_VARIANT (t1); 1439 t2 = TYPE_MAIN_VARIANT (t2); 1440 1441 /* [dcl.init.ref] 1442 1443 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related 1444 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class 1445 of T2. */ 1446 return (same_type_p (t1, t2) 1447 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 1448 && DERIVED_FROM_P (t1, t2))); 1449 } 1450 1451 /* Returns nonzero if T1 is reference-compatible with T2. */ 1452 1453 static bool 1454 reference_compatible_p (tree t1, tree t2) 1455 { 1456 /* [dcl.init.ref] 1457 1458 "cv1 T1" is reference compatible with "cv2 T2" if 1459 * T1 is reference-related to T2 or 1460 * T2 is "noexcept function" and T1 is "function", where the 1461 function types are otherwise the same, 1462 and cv1 is the same cv-qualification as, or greater cv-qualification 1463 than, cv2. */ 1464 return ((reference_related_p (t1, t2) 1465 || fnptr_conv_p (t1, t2)) 1466 && at_least_as_qualified_p (t1, t2)); 1467 } 1468 1469 /* A reference of the indicated TYPE is being bound directly to the 1470 expression represented by the implicit conversion sequence CONV. 1471 Return a conversion sequence for this binding. */ 1472 1473 static conversion * 1474 direct_reference_binding (tree type, conversion *conv) 1475 { 1476 tree t; 1477 1478 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE); 1479 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE); 1480 1481 t = TREE_TYPE (type); 1482 1483 if (conv->kind == ck_identity) 1484 /* Mark the identity conv as to not decay to rvalue. */ 1485 conv->rvaluedness_matches_p = true; 1486 1487 /* [over.ics.rank] 1488 1489 When a parameter of reference type binds directly 1490 (_dcl.init.ref_) to an argument expression, the implicit 1491 conversion sequence is the identity conversion, unless the 1492 argument expression has a type that is a derived class of the 1493 parameter type, in which case the implicit conversion sequence is 1494 a derived-to-base Conversion. 1495 1496 If the parameter binds directly to the result of applying a 1497 conversion function to the argument expression, the implicit 1498 conversion sequence is a user-defined conversion sequence 1499 (_over.ics.user_), with the second standard conversion sequence 1500 either an identity conversion or, if the conversion function 1501 returns an entity of a type that is a derived class of the 1502 parameter type, a derived-to-base conversion. */ 1503 if (is_properly_derived_from (conv->type, t)) 1504 { 1505 /* Represent the derived-to-base conversion. */ 1506 conv = build_conv (ck_base, t, conv); 1507 /* We will actually be binding to the base-class subobject in 1508 the derived class, so we mark this conversion appropriately. 1509 That way, convert_like knows not to generate a temporary. */ 1510 conv->need_temporary_p = false; 1511 } 1512 1513 return build_conv (ck_ref_bind, type, conv); 1514 } 1515 1516 /* Returns the conversion path from type FROM to reference type TO for 1517 purposes of reference binding. For lvalue binding, either pass a 1518 reference type to FROM or an lvalue expression to EXPR. If the 1519 reference will be bound to a temporary, NEED_TEMPORARY_P is set for 1520 the conversion returned. If C_CAST_P is true, this 1521 conversion is coming from a C-style cast. */ 1522 1523 static conversion * 1524 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags, 1525 tsubst_flags_t complain) 1526 { 1527 conversion *conv = NULL; 1528 tree to = TREE_TYPE (rto); 1529 tree from = rfrom; 1530 tree tfrom; 1531 bool related_p; 1532 bool compatible_p; 1533 cp_lvalue_kind gl_kind; 1534 bool is_lvalue; 1535 1536 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr)) 1537 { 1538 expr = instantiate_type (to, expr, tf_none); 1539 if (expr == error_mark_node) 1540 return NULL; 1541 from = TREE_TYPE (expr); 1542 } 1543 1544 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1545 { 1546 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS); 1547 /* DR 1288: Otherwise, if the initializer list has a single element 1548 of type E and ... [T's] referenced type is reference-related to E, 1549 the object or reference is initialized from that element... */ 1550 if (CONSTRUCTOR_NELTS (expr) == 1) 1551 { 1552 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 1553 if (error_operand_p (elt)) 1554 return NULL; 1555 tree etype = TREE_TYPE (elt); 1556 if (reference_related_p (to, etype)) 1557 { 1558 expr = elt; 1559 from = etype; 1560 goto skip; 1561 } 1562 } 1563 /* Otherwise, if T is a reference type, a prvalue temporary of the 1564 type referenced by T is copy-list-initialized or 1565 direct-list-initialized, depending on the kind of initialization 1566 for the reference, and the reference is bound to that temporary. */ 1567 conv = implicit_conversion (to, from, expr, c_cast_p, 1568 flags|LOOKUP_NO_TEMP_BIND, complain); 1569 skip:; 1570 } 1571 1572 if (TREE_CODE (from) == REFERENCE_TYPE) 1573 { 1574 from = TREE_TYPE (from); 1575 if (!TYPE_REF_IS_RVALUE (rfrom) 1576 || TREE_CODE (from) == FUNCTION_TYPE) 1577 gl_kind = clk_ordinary; 1578 else 1579 gl_kind = clk_rvalueref; 1580 } 1581 else if (expr) 1582 gl_kind = lvalue_kind (expr); 1583 else if (CLASS_TYPE_P (from) 1584 || TREE_CODE (from) == ARRAY_TYPE) 1585 gl_kind = clk_class; 1586 else 1587 gl_kind = clk_none; 1588 1589 /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND. */ 1590 if ((flags & LOOKUP_NO_TEMP_BIND) 1591 && (gl_kind & clk_class)) 1592 gl_kind = clk_none; 1593 1594 /* Same mask as real_lvalue_p. */ 1595 is_lvalue = gl_kind && !(gl_kind & (clk_rvalueref|clk_class)); 1596 1597 tfrom = from; 1598 if ((gl_kind & clk_bitfield) != 0) 1599 tfrom = unlowered_expr_type (expr); 1600 1601 /* Figure out whether or not the types are reference-related and 1602 reference compatible. We have to do this after stripping 1603 references from FROM. */ 1604 related_p = reference_related_p (to, tfrom); 1605 /* If this is a C cast, first convert to an appropriately qualified 1606 type, so that we can later do a const_cast to the desired type. */ 1607 if (related_p && c_cast_p 1608 && !at_least_as_qualified_p (to, tfrom)) 1609 to = cp_build_qualified_type (to, cp_type_quals (tfrom)); 1610 compatible_p = reference_compatible_p (to, tfrom); 1611 1612 /* Directly bind reference when target expression's type is compatible with 1613 the reference and expression is an lvalue. In DR391, the wording in 1614 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for 1615 const and rvalue references to rvalues of compatible class type. 1616 We should also do direct bindings for non-class xvalues. */ 1617 if ((related_p || compatible_p) && gl_kind) 1618 { 1619 /* [dcl.init.ref] 1620 1621 If the initializer expression 1622 1623 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1" 1624 is reference-compatible with "cv2 T2," 1625 1626 the reference is bound directly to the initializer expression 1627 lvalue. 1628 1629 [...] 1630 If the initializer expression is an rvalue, with T2 a class type, 1631 and "cv1 T1" is reference-compatible with "cv2 T2", the reference 1632 is bound to the object represented by the rvalue or to a sub-object 1633 within that object. */ 1634 1635 conv = build_identity_conv (tfrom, expr); 1636 conv = direct_reference_binding (rto, conv); 1637 1638 if (TREE_CODE (rfrom) == REFERENCE_TYPE) 1639 /* Handle rvalue reference to function properly. */ 1640 conv->rvaluedness_matches_p 1641 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom)); 1642 else 1643 conv->rvaluedness_matches_p 1644 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue); 1645 1646 if ((gl_kind & clk_bitfield) != 0 1647 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to))) 1648 /* For the purposes of overload resolution, we ignore the fact 1649 this expression is a bitfield or packed field. (In particular, 1650 [over.ics.ref] says specifically that a function with a 1651 non-const reference parameter is viable even if the 1652 argument is a bitfield.) 1653 1654 However, when we actually call the function we must create 1655 a temporary to which to bind the reference. If the 1656 reference is volatile, or isn't const, then we cannot make 1657 a temporary, so we just issue an error when the conversion 1658 actually occurs. */ 1659 conv->need_temporary_p = true; 1660 1661 /* Don't allow binding of lvalues (other than function lvalues) to 1662 rvalue references. */ 1663 if (is_lvalue && TYPE_REF_IS_RVALUE (rto) 1664 && TREE_CODE (to) != FUNCTION_TYPE) 1665 conv->bad_p = true; 1666 1667 /* Nor the reverse. */ 1668 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto) 1669 && (!CP_TYPE_CONST_NON_VOLATILE_P (to) 1670 || (flags & LOOKUP_NO_RVAL_BIND)) 1671 && TREE_CODE (to) != FUNCTION_TYPE) 1672 conv->bad_p = true; 1673 1674 if (!compatible_p) 1675 conv->bad_p = true; 1676 1677 return conv; 1678 } 1679 /* [class.conv.fct] A conversion function is never used to convert a 1680 (possibly cv-qualified) object to the (possibly cv-qualified) same 1681 object type (or a reference to it), to a (possibly cv-qualified) base 1682 class of that type (or a reference to it).... */ 1683 else if (CLASS_TYPE_P (from) && !related_p 1684 && !(flags & LOOKUP_NO_CONVERSION)) 1685 { 1686 /* [dcl.init.ref] 1687 1688 If the initializer expression 1689 1690 -- has a class type (i.e., T2 is a class type) can be 1691 implicitly converted to an lvalue of type "cv3 T3," where 1692 "cv1 T1" is reference-compatible with "cv3 T3". (this 1693 conversion is selected by enumerating the applicable 1694 conversion functions (_over.match.ref_) and choosing the 1695 best one through overload resolution. (_over.match_). 1696 1697 the reference is bound to the lvalue result of the conversion 1698 in the second case. */ 1699 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags, 1700 complain); 1701 if (cand) 1702 return cand->second_conv; 1703 } 1704 1705 /* From this point on, we conceptually need temporaries, even if we 1706 elide them. Only the cases above are "direct bindings". */ 1707 if (flags & LOOKUP_NO_TEMP_BIND) 1708 return NULL; 1709 1710 /* [over.ics.rank] 1711 1712 When a parameter of reference type is not bound directly to an 1713 argument expression, the conversion sequence is the one required 1714 to convert the argument expression to the underlying type of the 1715 reference according to _over.best.ics_. Conceptually, this 1716 conversion sequence corresponds to copy-initializing a temporary 1717 of the underlying type with the argument expression. Any 1718 difference in top-level cv-qualification is subsumed by the 1719 initialization itself and does not constitute a conversion. */ 1720 1721 /* [dcl.init.ref] 1722 1723 Otherwise, the reference shall be an lvalue reference to a 1724 non-volatile const type, or the reference shall be an rvalue 1725 reference. 1726 1727 We try below to treat this as a bad conversion to improve diagnostics, 1728 but if TO is an incomplete class, we need to reject this conversion 1729 now to avoid unnecessary instantiation. */ 1730 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto) 1731 && !COMPLETE_TYPE_P (to)) 1732 return NULL; 1733 1734 /* We're generating a temporary now, but don't bind any more in the 1735 conversion (specifically, don't slice the temporary returned by a 1736 conversion operator). */ 1737 flags |= LOOKUP_NO_TEMP_BIND; 1738 1739 /* Core issue 899: When [copy-]initializing a temporary to be bound 1740 to the first parameter of a copy constructor (12.8) called with 1741 a single argument in the context of direct-initialization, 1742 explicit conversion functions are also considered. 1743 1744 So don't set LOOKUP_ONLYCONVERTING in that case. */ 1745 if (!(flags & LOOKUP_COPY_PARM)) 1746 flags |= LOOKUP_ONLYCONVERTING; 1747 1748 if (!conv) 1749 conv = implicit_conversion (to, from, expr, c_cast_p, 1750 flags, complain); 1751 if (!conv) 1752 return NULL; 1753 1754 if (conv->user_conv_p) 1755 { 1756 /* If initializing the temporary used a conversion function, 1757 recalculate the second conversion sequence. */ 1758 for (conversion *t = conv; t; t = next_conversion (t)) 1759 if (t->kind == ck_user 1760 && DECL_CONV_FN_P (t->cand->fn)) 1761 { 1762 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn)); 1763 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND; 1764 conversion *new_second 1765 = reference_binding (rto, ftype, NULL_TREE, c_cast_p, 1766 sflags, complain); 1767 if (!new_second) 1768 return NULL; 1769 return merge_conversion_sequences (t, new_second); 1770 } 1771 } 1772 1773 conv = build_conv (ck_ref_bind, rto, conv); 1774 /* This reference binding, unlike those above, requires the 1775 creation of a temporary. */ 1776 conv->need_temporary_p = true; 1777 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto); 1778 1779 /* [dcl.init.ref] 1780 1781 Otherwise, the reference shall be an lvalue reference to a 1782 non-volatile const type, or the reference shall be an rvalue 1783 reference. */ 1784 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)) 1785 conv->bad_p = true; 1786 1787 /* [dcl.init.ref] 1788 1789 Otherwise, a temporary of type "cv1 T1" is created and 1790 initialized from the initializer expression using the rules for a 1791 non-reference copy initialization. If T1 is reference-related to 1792 T2, cv1 must be the same cv-qualification as, or greater 1793 cv-qualification than, cv2; otherwise, the program is ill-formed. */ 1794 if (related_p && !at_least_as_qualified_p (to, from)) 1795 conv->bad_p = true; 1796 1797 return conv; 1798 } 1799 1800 /* Returns the implicit conversion sequence (see [over.ics]) from type 1801 FROM to type TO. The optional expression EXPR may affect the 1802 conversion. FLAGS are the usual overloading flags. If C_CAST_P is 1803 true, this conversion is coming from a C-style cast. */ 1804 1805 static conversion * 1806 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p, 1807 int flags, tsubst_flags_t complain) 1808 { 1809 conversion *conv; 1810 1811 if (from == error_mark_node || to == error_mark_node 1812 || expr == error_mark_node) 1813 return NULL; 1814 1815 /* Other flags only apply to the primary function in overload 1816 resolution, or after we've chosen one. */ 1817 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM 1818 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE 1819 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL); 1820 1821 /* FIXME: actually we don't want warnings either, but we can't just 1822 have 'complain &= ~(tf_warning|tf_error)' because it would cause 1823 the regression of, eg, g++.old-deja/g++.benjamin/16077.C. 1824 We really ought not to issue that warning until we've committed 1825 to that conversion. */ 1826 complain &= ~tf_error; 1827 1828 /* Call reshape_init early to remove redundant braces. */ 1829 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr) 1830 && CLASS_TYPE_P (to) 1831 && COMPLETE_TYPE_P (complete_type (to)) 1832 && !CLASSTYPE_NON_AGGREGATE (to)) 1833 { 1834 expr = reshape_init (to, expr, complain); 1835 if (expr == error_mark_node) 1836 return NULL; 1837 from = TREE_TYPE (expr); 1838 } 1839 1840 if (TREE_CODE (to) == REFERENCE_TYPE) 1841 conv = reference_binding (to, from, expr, c_cast_p, flags, complain); 1842 else 1843 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain); 1844 1845 if (conv) 1846 return conv; 1847 1848 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)) 1849 { 1850 if (is_std_init_list (to)) 1851 return build_list_conv (to, expr, flags, complain); 1852 1853 /* As an extension, allow list-initialization of _Complex. */ 1854 if (TREE_CODE (to) == COMPLEX_TYPE) 1855 { 1856 conv = build_complex_conv (to, expr, flags, complain); 1857 if (conv) 1858 return conv; 1859 } 1860 1861 /* Allow conversion from an initializer-list with one element to a 1862 scalar type. */ 1863 if (SCALAR_TYPE_P (to)) 1864 { 1865 int nelts = CONSTRUCTOR_NELTS (expr); 1866 tree elt; 1867 1868 if (nelts == 0) 1869 elt = build_value_init (to, tf_none); 1870 else if (nelts == 1) 1871 elt = CONSTRUCTOR_ELT (expr, 0)->value; 1872 else 1873 elt = error_mark_node; 1874 1875 conv = implicit_conversion (to, TREE_TYPE (elt), elt, 1876 c_cast_p, flags, complain); 1877 if (conv) 1878 { 1879 conv->check_narrowing = true; 1880 if (BRACE_ENCLOSED_INITIALIZER_P (elt)) 1881 /* Too many levels of braces, i.e. '{{1}}'. */ 1882 conv->bad_p = true; 1883 return conv; 1884 } 1885 } 1886 else if (TREE_CODE (to) == ARRAY_TYPE) 1887 return build_array_conv (to, expr, flags, complain); 1888 } 1889 1890 if (expr != NULL_TREE 1891 && (MAYBE_CLASS_TYPE_P (from) 1892 || MAYBE_CLASS_TYPE_P (to)) 1893 && (flags & LOOKUP_NO_CONVERSION) == 0) 1894 { 1895 struct z_candidate *cand; 1896 1897 if (CLASS_TYPE_P (to) 1898 && BRACE_ENCLOSED_INITIALIZER_P (expr) 1899 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))) 1900 return build_aggr_conv (to, expr, flags, complain); 1901 1902 cand = build_user_type_conversion_1 (to, expr, flags, complain); 1903 if (cand) 1904 { 1905 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 1906 && CONSTRUCTOR_NELTS (expr) == 1 1907 && !is_list_ctor (cand->fn)) 1908 { 1909 /* "If C is not an initializer-list constructor and the 1910 initializer list has a single element of type cv U, where U is 1911 X or a class derived from X, the implicit conversion sequence 1912 has Exact Match rank if U is X, or Conversion rank if U is 1913 derived from X." */ 1914 tree elt = CONSTRUCTOR_ELT (expr, 0)->value; 1915 tree elttype = TREE_TYPE (elt); 1916 if (reference_related_p (to, elttype)) 1917 return implicit_conversion (to, elttype, elt, 1918 c_cast_p, flags, complain); 1919 } 1920 conv = cand->second_conv; 1921 } 1922 1923 /* We used to try to bind a reference to a temporary here, but that 1924 is now handled after the recursive call to this function at the end 1925 of reference_binding. */ 1926 return conv; 1927 } 1928 1929 return NULL; 1930 } 1931 1932 /* Add a new entry to the list of candidates. Used by the add_*_candidate 1933 functions. ARGS will not be changed until a single candidate is 1934 selected. */ 1935 1936 static struct z_candidate * 1937 add_candidate (struct z_candidate **candidates, 1938 tree fn, tree first_arg, const vec<tree, va_gc> *args, 1939 size_t num_convs, conversion **convs, 1940 tree access_path, tree conversion_path, 1941 int viable, struct rejection_reason *reason, 1942 int flags) 1943 { 1944 struct z_candidate *cand = (struct z_candidate *) 1945 conversion_obstack_alloc (sizeof (struct z_candidate)); 1946 1947 cand->fn = fn; 1948 cand->first_arg = first_arg; 1949 cand->args = args; 1950 cand->convs = convs; 1951 cand->num_convs = num_convs; 1952 cand->access_path = access_path; 1953 cand->conversion_path = conversion_path; 1954 cand->viable = viable; 1955 cand->reason = reason; 1956 cand->next = *candidates; 1957 cand->flags = flags; 1958 *candidates = cand; 1959 1960 return cand; 1961 } 1962 1963 /* Return the number of remaining arguments in the parameter list 1964 beginning with ARG. */ 1965 1966 int 1967 remaining_arguments (tree arg) 1968 { 1969 int n; 1970 1971 for (n = 0; arg != NULL_TREE && arg != void_list_node; 1972 arg = TREE_CHAIN (arg)) 1973 n++; 1974 1975 return n; 1976 } 1977 1978 /* Create an overload candidate for the function or method FN called 1979 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES. 1980 FLAGS is passed on to implicit_conversion. 1981 1982 This does not change ARGS. 1983 1984 CTYPE, if non-NULL, is the type we want to pretend this function 1985 comes from for purposes of overload resolution. */ 1986 1987 static struct z_candidate * 1988 add_function_candidate (struct z_candidate **candidates, 1989 tree fn, tree ctype, tree first_arg, 1990 const vec<tree, va_gc> *args, tree access_path, 1991 tree conversion_path, int flags, 1992 tsubst_flags_t complain) 1993 { 1994 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn)); 1995 int i, len; 1996 conversion **convs; 1997 tree parmnode; 1998 tree orig_first_arg = first_arg; 1999 int skip; 2000 int viable = 1; 2001 struct rejection_reason *reason = NULL; 2002 2003 /* At this point we should not see any functions which haven't been 2004 explicitly declared, except for friend functions which will have 2005 been found using argument dependent lookup. */ 2006 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn)); 2007 2008 /* The `this', `in_chrg' and VTT arguments to constructors are not 2009 considered in overload resolution. */ 2010 if (DECL_CONSTRUCTOR_P (fn)) 2011 { 2012 if (ctor_omit_inherited_parms (fn)) 2013 /* Bring back parameters omitted from an inherited ctor. */ 2014 parmlist = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn)); 2015 else 2016 parmlist = skip_artificial_parms_for (fn, parmlist); 2017 skip = num_artificial_parms_for (fn); 2018 if (skip > 0 && first_arg != NULL_TREE) 2019 { 2020 --skip; 2021 first_arg = NULL_TREE; 2022 } 2023 } 2024 else 2025 skip = 0; 2026 2027 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0); 2028 convs = alloc_conversions (len); 2029 2030 /* 13.3.2 - Viable functions [over.match.viable] 2031 First, to be a viable function, a candidate function shall have enough 2032 parameters to agree in number with the arguments in the list. 2033 2034 We need to check this first; otherwise, checking the ICSes might cause 2035 us to produce an ill-formed template instantiation. */ 2036 2037 parmnode = parmlist; 2038 for (i = 0; i < len; ++i) 2039 { 2040 if (parmnode == NULL_TREE || parmnode == void_list_node) 2041 break; 2042 parmnode = TREE_CHAIN (parmnode); 2043 } 2044 2045 if ((i < len && parmnode) 2046 || !sufficient_parms_p (parmnode)) 2047 { 2048 int remaining = remaining_arguments (parmnode); 2049 viable = 0; 2050 reason = arity_rejection (first_arg, i + remaining, len); 2051 } 2052 2053 /* An inherited constructor (12.6.3 [class.inhctor.init]) that has a first 2054 parameter of type "reference to cv C" (including such a constructor 2055 instantiated from a template) is excluded from the set of candidate 2056 functions when used to construct an object of type D with an argument list 2057 containing a single argument if C is reference-related to D. */ 2058 if (viable && len == 1 && parmlist && DECL_CONSTRUCTOR_P (fn) 2059 && flag_new_inheriting_ctors 2060 && DECL_INHERITED_CTOR (fn)) 2061 { 2062 tree ptype = non_reference (TREE_VALUE (parmlist)); 2063 tree dtype = DECL_CONTEXT (fn); 2064 tree btype = DECL_INHERITED_CTOR_BASE (fn); 2065 if (reference_related_p (ptype, dtype) 2066 && reference_related_p (btype, ptype)) 2067 { 2068 viable = false; 2069 reason = inherited_ctor_rejection (); 2070 } 2071 } 2072 2073 /* Second, for a function to be viable, its constraints must be 2074 satisfied. */ 2075 if (flag_concepts && viable 2076 && !constraints_satisfied_p (fn)) 2077 { 2078 reason = constraint_failure (fn); 2079 viable = false; 2080 } 2081 2082 /* When looking for a function from a subobject from an implicit 2083 copy/move constructor/operator=, don't consider anything that takes (a 2084 reference to) an unrelated type. See c++/44909 and core 1092. */ 2085 if (viable && parmlist && (flags & LOOKUP_DEFAULTED)) 2086 { 2087 if (DECL_CONSTRUCTOR_P (fn)) 2088 i = 1; 2089 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 2090 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR)) 2091 i = 2; 2092 else 2093 i = 0; 2094 if (i && len == i) 2095 { 2096 parmnode = chain_index (i-1, parmlist); 2097 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)), 2098 ctype)) 2099 viable = 0; 2100 } 2101 2102 /* This only applies at the top level. */ 2103 flags &= ~LOOKUP_DEFAULTED; 2104 } 2105 2106 if (! viable) 2107 goto out; 2108 2109 /* Third, for F to be a viable function, there shall exist for each 2110 argument an implicit conversion sequence that converts that argument 2111 to the corresponding parameter of F. */ 2112 2113 parmnode = parmlist; 2114 2115 for (i = 0; i < len; ++i) 2116 { 2117 tree argtype, to_type; 2118 tree arg; 2119 conversion *t; 2120 int is_this; 2121 2122 if (parmnode == void_list_node) 2123 break; 2124 2125 if (i == 0 && first_arg != NULL_TREE) 2126 arg = first_arg; 2127 else 2128 arg = CONST_CAST_TREE ( 2129 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]); 2130 argtype = lvalue_type (arg); 2131 2132 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 2133 && ! DECL_CONSTRUCTOR_P (fn)); 2134 2135 if (parmnode) 2136 { 2137 tree parmtype = TREE_VALUE (parmnode); 2138 int lflags = flags; 2139 2140 parmnode = TREE_CHAIN (parmnode); 2141 2142 /* The type of the implicit object parameter ('this') for 2143 overload resolution is not always the same as for the 2144 function itself; conversion functions are considered to 2145 be members of the class being converted, and functions 2146 introduced by a using-declaration are considered to be 2147 members of the class that uses them. 2148 2149 Since build_over_call ignores the ICS for the `this' 2150 parameter, we can just change the parm type. */ 2151 if (ctype && is_this) 2152 { 2153 parmtype = cp_build_qualified_type 2154 (ctype, cp_type_quals (TREE_TYPE (parmtype))); 2155 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn))) 2156 { 2157 /* If the function has a ref-qualifier, the implicit 2158 object parameter has reference type. */ 2159 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn)); 2160 parmtype = cp_build_reference_type (parmtype, rv); 2161 /* The special handling of 'this' conversions in compare_ics 2162 does not apply if there is a ref-qualifier. */ 2163 is_this = false; 2164 } 2165 else 2166 { 2167 parmtype = build_pointer_type (parmtype); 2168 /* We don't use build_this here because we don't want to 2169 capture the object argument until we've chosen a 2170 non-static member function. */ 2171 arg = build_address (arg); 2172 argtype = lvalue_type (arg); 2173 } 2174 } 2175 2176 /* Core issue 899: When [copy-]initializing a temporary to be bound 2177 to the first parameter of a copy constructor (12.8) called with 2178 a single argument in the context of direct-initialization, 2179 explicit conversion functions are also considered. 2180 2181 So set LOOKUP_COPY_PARM to let reference_binding know that 2182 it's being called in that context. We generalize the above 2183 to handle move constructors and template constructors as well; 2184 the standardese should soon be updated similarly. */ 2185 if (ctype && i == 0 && (len-skip == 1) 2186 && DECL_CONSTRUCTOR_P (fn) 2187 && parmtype != error_mark_node 2188 && (same_type_ignoring_top_level_qualifiers_p 2189 (non_reference (parmtype), ctype))) 2190 { 2191 if (!(flags & LOOKUP_ONLYCONVERTING)) 2192 lflags |= LOOKUP_COPY_PARM; 2193 /* We allow user-defined conversions within init-lists, but 2194 don't list-initialize the copy parm, as that would mean 2195 using two levels of braces for the same type. */ 2196 if ((flags & LOOKUP_LIST_INIT_CTOR) 2197 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 2198 lflags |= LOOKUP_NO_CONVERSION; 2199 } 2200 else 2201 lflags |= LOOKUP_ONLYCONVERTING; 2202 2203 t = implicit_conversion (parmtype, argtype, arg, 2204 /*c_cast_p=*/false, lflags, complain); 2205 to_type = parmtype; 2206 } 2207 else 2208 { 2209 t = build_identity_conv (argtype, arg); 2210 t->ellipsis_p = true; 2211 to_type = argtype; 2212 } 2213 2214 if (t && is_this) 2215 t->this_p = true; 2216 2217 convs[i] = t; 2218 if (! t) 2219 { 2220 viable = 0; 2221 reason = arg_conversion_rejection (first_arg, i, argtype, to_type); 2222 break; 2223 } 2224 2225 if (t->bad_p) 2226 { 2227 viable = -1; 2228 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type); 2229 } 2230 } 2231 2232 out: 2233 return add_candidate (candidates, fn, orig_first_arg, args, len, convs, 2234 access_path, conversion_path, viable, reason, flags); 2235 } 2236 2237 /* Create an overload candidate for the conversion function FN which will 2238 be invoked for expression OBJ, producing a pointer-to-function which 2239 will in turn be called with the argument list FIRST_ARG/ARGLIST, 2240 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 2241 passed on to implicit_conversion. 2242 2243 Actually, we don't really care about FN; we care about the type it 2244 converts to. There may be multiple conversion functions that will 2245 convert to that type, and we rely on build_user_type_conversion_1 to 2246 choose the best one; so when we create our candidate, we record the type 2247 instead of the function. */ 2248 2249 static struct z_candidate * 2250 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj, 2251 const vec<tree, va_gc> *arglist, 2252 tree access_path, tree conversion_path, 2253 tsubst_flags_t complain) 2254 { 2255 tree totype = TREE_TYPE (TREE_TYPE (fn)); 2256 int i, len, viable, flags; 2257 tree parmlist, parmnode; 2258 conversion **convs; 2259 struct rejection_reason *reason; 2260 2261 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; ) 2262 parmlist = TREE_TYPE (parmlist); 2263 parmlist = TYPE_ARG_TYPES (parmlist); 2264 2265 len = vec_safe_length (arglist) + 1; 2266 convs = alloc_conversions (len); 2267 parmnode = parmlist; 2268 viable = 1; 2269 flags = LOOKUP_IMPLICIT; 2270 reason = NULL; 2271 2272 /* Don't bother looking up the same type twice. */ 2273 if (*candidates && (*candidates)->fn == totype) 2274 return NULL; 2275 2276 for (i = 0; i < len; ++i) 2277 { 2278 tree arg, argtype, convert_type = NULL_TREE; 2279 conversion *t; 2280 2281 if (i == 0) 2282 arg = obj; 2283 else 2284 arg = (*arglist)[i - 1]; 2285 argtype = lvalue_type (arg); 2286 2287 if (i == 0) 2288 { 2289 t = build_identity_conv (argtype, NULL_TREE); 2290 t = build_conv (ck_user, totype, t); 2291 /* Leave the 'cand' field null; we'll figure out the conversion in 2292 convert_like_real if this candidate is chosen. */ 2293 convert_type = totype; 2294 } 2295 else if (parmnode == void_list_node) 2296 break; 2297 else if (parmnode) 2298 { 2299 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, 2300 /*c_cast_p=*/false, flags, complain); 2301 convert_type = TREE_VALUE (parmnode); 2302 } 2303 else 2304 { 2305 t = build_identity_conv (argtype, arg); 2306 t->ellipsis_p = true; 2307 convert_type = argtype; 2308 } 2309 2310 convs[i] = t; 2311 if (! t) 2312 break; 2313 2314 if (t->bad_p) 2315 { 2316 viable = -1; 2317 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type); 2318 } 2319 2320 if (i == 0) 2321 continue; 2322 2323 if (parmnode) 2324 parmnode = TREE_CHAIN (parmnode); 2325 } 2326 2327 if (i < len 2328 || ! sufficient_parms_p (parmnode)) 2329 { 2330 int remaining = remaining_arguments (parmnode); 2331 viable = 0; 2332 reason = arity_rejection (NULL_TREE, i + remaining, len); 2333 } 2334 2335 return add_candidate (candidates, totype, obj, arglist, len, convs, 2336 access_path, conversion_path, viable, reason, flags); 2337 } 2338 2339 static void 2340 build_builtin_candidate (struct z_candidate **candidates, tree fnname, 2341 tree type1, tree type2, tree *args, tree *argtypes, 2342 int flags, tsubst_flags_t complain) 2343 { 2344 conversion *t; 2345 conversion **convs; 2346 size_t num_convs; 2347 int viable = 1, i; 2348 tree types[2]; 2349 struct rejection_reason *reason = NULL; 2350 2351 types[0] = type1; 2352 types[1] = type2; 2353 2354 num_convs = args[2] ? 3 : (args[1] ? 2 : 1); 2355 convs = alloc_conversions (num_convs); 2356 2357 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit 2358 conversion ops are allowed. We handle that here by just checking for 2359 boolean_type_node because other operators don't ask for it. COND_EXPR 2360 also does contextual conversion to bool for the first operand, but we 2361 handle that in build_conditional_expr, and type1 here is operand 2. */ 2362 if (type1 != boolean_type_node) 2363 flags |= LOOKUP_ONLYCONVERTING; 2364 2365 for (i = 0; i < 2; ++i) 2366 { 2367 if (! args[i]) 2368 break; 2369 2370 t = implicit_conversion (types[i], argtypes[i], args[i], 2371 /*c_cast_p=*/false, flags, complain); 2372 if (! t) 2373 { 2374 viable = 0; 2375 /* We need something for printing the candidate. */ 2376 t = build_identity_conv (types[i], NULL_TREE); 2377 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], 2378 types[i]); 2379 } 2380 else if (t->bad_p) 2381 { 2382 viable = 0; 2383 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i], 2384 types[i]); 2385 } 2386 convs[i] = t; 2387 } 2388 2389 /* For COND_EXPR we rearranged the arguments; undo that now. */ 2390 if (args[2]) 2391 { 2392 convs[2] = convs[1]; 2393 convs[1] = convs[0]; 2394 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], 2395 /*c_cast_p=*/false, flags, 2396 complain); 2397 if (t) 2398 convs[0] = t; 2399 else 2400 { 2401 viable = 0; 2402 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2], 2403 boolean_type_node); 2404 } 2405 } 2406 2407 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL, 2408 num_convs, convs, 2409 /*access_path=*/NULL_TREE, 2410 /*conversion_path=*/NULL_TREE, 2411 viable, reason, flags); 2412 } 2413 2414 static bool 2415 is_complete (tree t) 2416 { 2417 return COMPLETE_TYPE_P (complete_type (t)); 2418 } 2419 2420 /* Returns nonzero if TYPE is a promoted arithmetic type. */ 2421 2422 static bool 2423 promoted_arithmetic_type_p (tree type) 2424 { 2425 /* [over.built] 2426 2427 In this section, the term promoted integral type is used to refer 2428 to those integral types which are preserved by integral promotion 2429 (including e.g. int and long but excluding e.g. char). 2430 Similarly, the term promoted arithmetic type refers to promoted 2431 integral types plus floating types. */ 2432 return ((CP_INTEGRAL_TYPE_P (type) 2433 && same_type_p (type_promotes_to (type), type)) 2434 || TREE_CODE (type) == REAL_TYPE); 2435 } 2436 2437 /* Create any builtin operator overload candidates for the operator in 2438 question given the converted operand types TYPE1 and TYPE2. The other 2439 args are passed through from add_builtin_candidates to 2440 build_builtin_candidate. 2441 2442 TYPE1 and TYPE2 may not be permissible, and we must filter them. 2443 If CODE is requires candidates operands of the same type of the kind 2444 of which TYPE1 and TYPE2 are, we add both candidates 2445 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */ 2446 2447 static void 2448 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code, 2449 enum tree_code code2, tree fnname, tree type1, 2450 tree type2, tree *args, tree *argtypes, int flags, 2451 tsubst_flags_t complain) 2452 { 2453 switch (code) 2454 { 2455 case POSTINCREMENT_EXPR: 2456 case POSTDECREMENT_EXPR: 2457 args[1] = integer_zero_node; 2458 type2 = integer_type_node; 2459 break; 2460 default: 2461 break; 2462 } 2463 2464 switch (code) 2465 { 2466 2467 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2468 and VQ is either volatile or empty, there exist candidate operator 2469 functions of the form 2470 VQ T& operator++(VQ T&); 2471 T operator++(VQ T&, int); 2472 5 For every pair T, VQ), where T is an enumeration type or an arithmetic 2473 type other than bool, and VQ is either volatile or empty, there exist 2474 candidate operator functions of the form 2475 VQ T& operator--(VQ T&); 2476 T operator--(VQ T&, int); 2477 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified 2478 complete object type, and VQ is either volatile or empty, there exist 2479 candidate operator functions of the form 2480 T*VQ& operator++(T*VQ&); 2481 T*VQ& operator--(T*VQ&); 2482 T* operator++(T*VQ&, int); 2483 T* operator--(T*VQ&, int); */ 2484 2485 case POSTDECREMENT_EXPR: 2486 case PREDECREMENT_EXPR: 2487 if (TREE_CODE (type1) == BOOLEAN_TYPE) 2488 return; 2489 /* FALLTHRU */ 2490 case POSTINCREMENT_EXPR: 2491 case PREINCREMENT_EXPR: 2492 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1)) 2493 { 2494 type1 = build_reference_type (type1); 2495 break; 2496 } 2497 return; 2498 2499 /* 7 For every cv-qualified or cv-unqualified object type T, there 2500 exist candidate operator functions of the form 2501 2502 T& operator*(T*); 2503 2504 8 For every function type T, there exist candidate operator functions of 2505 the form 2506 T& operator*(T*); */ 2507 2508 case INDIRECT_REF: 2509 if (TYPE_PTR_P (type1) 2510 && (TYPE_PTROB_P (type1) 2511 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)) 2512 break; 2513 return; 2514 2515 /* 9 For every type T, there exist candidate operator functions of the form 2516 T* operator+(T*); 2517 2518 10For every promoted arithmetic type T, there exist candidate operator 2519 functions of the form 2520 T operator+(T); 2521 T operator-(T); */ 2522 2523 case UNARY_PLUS_EXPR: /* unary + */ 2524 if (TYPE_PTR_P (type1)) 2525 break; 2526 /* FALLTHRU */ 2527 case NEGATE_EXPR: 2528 if (ARITHMETIC_TYPE_P (type1)) 2529 break; 2530 return; 2531 2532 /* 11For every promoted integral type T, there exist candidate operator 2533 functions of the form 2534 T operator~(T); */ 2535 2536 case BIT_NOT_EXPR: 2537 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1)) 2538 break; 2539 return; 2540 2541 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1 2542 is the same type as C2 or is a derived class of C2, T is a complete 2543 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 2544 there exist candidate operator functions of the form 2545 CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 2546 where CV12 is the union of CV1 and CV2. */ 2547 2548 case MEMBER_REF: 2549 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2)) 2550 { 2551 tree c1 = TREE_TYPE (type1); 2552 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2); 2553 2554 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1) 2555 && (TYPE_PTRMEMFUNC_P (type2) 2556 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2)))) 2557 break; 2558 } 2559 return; 2560 2561 /* 13For every pair of promoted arithmetic types L and R, there exist can- 2562 didate operator functions of the form 2563 LR operator*(L, R); 2564 LR operator/(L, R); 2565 LR operator+(L, R); 2566 LR operator-(L, R); 2567 bool operator<(L, R); 2568 bool operator>(L, R); 2569 bool operator<=(L, R); 2570 bool operator>=(L, R); 2571 bool operator==(L, R); 2572 bool operator!=(L, R); 2573 where LR is the result of the usual arithmetic conversions between 2574 types L and R. 2575 2576 14For every pair of types T and I, where T is a cv-qualified or cv- 2577 unqualified complete object type and I is a promoted integral type, 2578 there exist candidate operator functions of the form 2579 T* operator+(T*, I); 2580 T& operator[](T*, I); 2581 T* operator-(T*, I); 2582 T* operator+(I, T*); 2583 T& operator[](I, T*); 2584 2585 15For every T, where T is a pointer to complete object type, there exist 2586 candidate operator functions of the form112) 2587 ptrdiff_t operator-(T, T); 2588 2589 16For every pointer or enumeration type T, there exist candidate operator 2590 functions of the form 2591 bool operator<(T, T); 2592 bool operator>(T, T); 2593 bool operator<=(T, T); 2594 bool operator>=(T, T); 2595 bool operator==(T, T); 2596 bool operator!=(T, T); 2597 2598 17For every pointer to member type T, there exist candidate operator 2599 functions of the form 2600 bool operator==(T, T); 2601 bool operator!=(T, T); */ 2602 2603 case MINUS_EXPR: 2604 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2)) 2605 break; 2606 if (TYPE_PTROB_P (type1) 2607 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2608 { 2609 type2 = ptrdiff_type_node; 2610 break; 2611 } 2612 /* FALLTHRU */ 2613 case MULT_EXPR: 2614 case TRUNC_DIV_EXPR: 2615 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2616 break; 2617 return; 2618 2619 case EQ_EXPR: 2620 case NE_EXPR: 2621 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2622 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))) 2623 break; 2624 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1])) 2625 { 2626 type2 = type1; 2627 break; 2628 } 2629 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0])) 2630 { 2631 type1 = type2; 2632 break; 2633 } 2634 /* Fall through. */ 2635 case LT_EXPR: 2636 case GT_EXPR: 2637 case LE_EXPR: 2638 case GE_EXPR: 2639 case MAX_EXPR: 2640 case MIN_EXPR: 2641 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2642 break; 2643 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2644 break; 2645 if (TREE_CODE (type1) == ENUMERAL_TYPE 2646 && TREE_CODE (type2) == ENUMERAL_TYPE) 2647 break; 2648 if (TYPE_PTR_P (type1) 2649 && null_ptr_cst_p (args[1])) 2650 { 2651 type2 = type1; 2652 break; 2653 } 2654 if (null_ptr_cst_p (args[0]) 2655 && TYPE_PTR_P (type2)) 2656 { 2657 type1 = type2; 2658 break; 2659 } 2660 return; 2661 2662 case PLUS_EXPR: 2663 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2664 break; 2665 /* FALLTHRU */ 2666 case ARRAY_REF: 2667 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2)) 2668 { 2669 type1 = ptrdiff_type_node; 2670 break; 2671 } 2672 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2673 { 2674 type2 = ptrdiff_type_node; 2675 break; 2676 } 2677 return; 2678 2679 /* 18For every pair of promoted integral types L and R, there exist candi- 2680 date operator functions of the form 2681 LR operator%(L, R); 2682 LR operator&(L, R); 2683 LR operator^(L, R); 2684 LR operator|(L, R); 2685 L operator<<(L, R); 2686 L operator>>(L, R); 2687 where LR is the result of the usual arithmetic conversions between 2688 types L and R. */ 2689 2690 case TRUNC_MOD_EXPR: 2691 case BIT_AND_EXPR: 2692 case BIT_IOR_EXPR: 2693 case BIT_XOR_EXPR: 2694 case LSHIFT_EXPR: 2695 case RSHIFT_EXPR: 2696 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2697 break; 2698 return; 2699 2700 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration 2701 type, VQ is either volatile or empty, and R is a promoted arithmetic 2702 type, there exist candidate operator functions of the form 2703 VQ L& operator=(VQ L&, R); 2704 VQ L& operator*=(VQ L&, R); 2705 VQ L& operator/=(VQ L&, R); 2706 VQ L& operator+=(VQ L&, R); 2707 VQ L& operator-=(VQ L&, R); 2708 2709 20For every pair T, VQ), where T is any type and VQ is either volatile 2710 or empty, there exist candidate operator functions of the form 2711 T*VQ& operator=(T*VQ&, T*); 2712 2713 21For every pair T, VQ), where T is a pointer to member type and VQ is 2714 either volatile or empty, there exist candidate operator functions of 2715 the form 2716 VQ T& operator=(VQ T&, T); 2717 2718 22For every triple T, VQ, I), where T is a cv-qualified or cv- 2719 unqualified complete object type, VQ is either volatile or empty, and 2720 I is a promoted integral type, there exist candidate operator func- 2721 tions of the form 2722 T*VQ& operator+=(T*VQ&, I); 2723 T*VQ& operator-=(T*VQ&, I); 2724 2725 23For every triple L, VQ, R), where L is an integral or enumeration 2726 type, VQ is either volatile or empty, and R is a promoted integral 2727 type, there exist candidate operator functions of the form 2728 2729 VQ L& operator%=(VQ L&, R); 2730 VQ L& operator<<=(VQ L&, R); 2731 VQ L& operator>>=(VQ L&, R); 2732 VQ L& operator&=(VQ L&, R); 2733 VQ L& operator^=(VQ L&, R); 2734 VQ L& operator|=(VQ L&, R); */ 2735 2736 case MODIFY_EXPR: 2737 switch (code2) 2738 { 2739 case PLUS_EXPR: 2740 case MINUS_EXPR: 2741 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2742 { 2743 type2 = ptrdiff_type_node; 2744 break; 2745 } 2746 /* FALLTHRU */ 2747 case MULT_EXPR: 2748 case TRUNC_DIV_EXPR: 2749 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2750 break; 2751 return; 2752 2753 case TRUNC_MOD_EXPR: 2754 case BIT_AND_EXPR: 2755 case BIT_IOR_EXPR: 2756 case BIT_XOR_EXPR: 2757 case LSHIFT_EXPR: 2758 case RSHIFT_EXPR: 2759 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2)) 2760 break; 2761 return; 2762 2763 case NOP_EXPR: 2764 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2)) 2765 break; 2766 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2)) 2767 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2768 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2769 || ((TYPE_PTRMEMFUNC_P (type1) 2770 || TYPE_PTR_P (type1)) 2771 && null_ptr_cst_p (args[1]))) 2772 { 2773 type2 = type1; 2774 break; 2775 } 2776 return; 2777 2778 default: 2779 gcc_unreachable (); 2780 } 2781 type1 = build_reference_type (type1); 2782 break; 2783 2784 case COND_EXPR: 2785 /* [over.built] 2786 2787 For every pair of promoted arithmetic types L and R, there 2788 exist candidate operator functions of the form 2789 2790 LR operator?(bool, L, R); 2791 2792 where LR is the result of the usual arithmetic conversions 2793 between types L and R. 2794 2795 For every type T, where T is a pointer or pointer-to-member 2796 type, there exist candidate operator functions of the form T 2797 operator?(bool, T, T); */ 2798 2799 if (promoted_arithmetic_type_p (type1) 2800 && promoted_arithmetic_type_p (type2)) 2801 /* That's OK. */ 2802 break; 2803 2804 /* Otherwise, the types should be pointers. */ 2805 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2)) 2806 return; 2807 2808 /* We don't check that the two types are the same; the logic 2809 below will actually create two candidates; one in which both 2810 parameter types are TYPE1, and one in which both parameter 2811 types are TYPE2. */ 2812 break; 2813 2814 case REALPART_EXPR: 2815 case IMAGPART_EXPR: 2816 if (ARITHMETIC_TYPE_P (type1)) 2817 break; 2818 return; 2819 2820 default: 2821 gcc_unreachable (); 2822 } 2823 2824 /* Make sure we don't create builtin candidates with dependent types. */ 2825 bool u1 = uses_template_parms (type1); 2826 bool u2 = type2 ? uses_template_parms (type2) : false; 2827 if (u1 || u2) 2828 { 2829 /* Try to recover if one of the types is non-dependent. But if 2830 there's only one type, there's nothing we can do. */ 2831 if (!type2) 2832 return; 2833 /* And we lose if both are dependent. */ 2834 if (u1 && u2) 2835 return; 2836 /* Or if they have different forms. */ 2837 if (TREE_CODE (type1) != TREE_CODE (type2)) 2838 return; 2839 2840 if (u1 && !u2) 2841 type1 = type2; 2842 else if (u2 && !u1) 2843 type2 = type1; 2844 } 2845 2846 /* If we're dealing with two pointer types or two enumeral types, 2847 we need candidates for both of them. */ 2848 if (type2 && !same_type_p (type1, type2) 2849 && TREE_CODE (type1) == TREE_CODE (type2) 2850 && (TREE_CODE (type1) == REFERENCE_TYPE 2851 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2)) 2852 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)) 2853 || TYPE_PTRMEMFUNC_P (type1) 2854 || MAYBE_CLASS_TYPE_P (type1) 2855 || TREE_CODE (type1) == ENUMERAL_TYPE)) 2856 { 2857 if (TYPE_PTR_OR_PTRMEM_P (type1)) 2858 { 2859 tree cptype = composite_pointer_type (type1, type2, 2860 error_mark_node, 2861 error_mark_node, 2862 CPO_CONVERSION, 2863 tf_none); 2864 if (cptype != error_mark_node) 2865 { 2866 build_builtin_candidate 2867 (candidates, fnname, cptype, cptype, args, argtypes, 2868 flags, complain); 2869 return; 2870 } 2871 } 2872 2873 build_builtin_candidate 2874 (candidates, fnname, type1, type1, args, argtypes, flags, complain); 2875 build_builtin_candidate 2876 (candidates, fnname, type2, type2, args, argtypes, flags, complain); 2877 return; 2878 } 2879 2880 build_builtin_candidate 2881 (candidates, fnname, type1, type2, args, argtypes, flags, complain); 2882 } 2883 2884 tree 2885 type_decays_to (tree type) 2886 { 2887 if (TREE_CODE (type) == ARRAY_TYPE) 2888 return build_pointer_type (TREE_TYPE (type)); 2889 if (TREE_CODE (type) == FUNCTION_TYPE) 2890 return build_pointer_type (type); 2891 return type; 2892 } 2893 2894 /* There are three conditions of builtin candidates: 2895 2896 1) bool-taking candidates. These are the same regardless of the input. 2897 2) pointer-pair taking candidates. These are generated for each type 2898 one of the input types converts to. 2899 3) arithmetic candidates. According to the standard, we should generate 2900 all of these, but I'm trying not to... 2901 2902 Here we generate a superset of the possible candidates for this particular 2903 case. That is a subset of the full set the standard defines, plus some 2904 other cases which the standard disallows. add_builtin_candidate will 2905 filter out the invalid set. */ 2906 2907 static void 2908 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code, 2909 enum tree_code code2, tree fnname, tree *args, 2910 int flags, tsubst_flags_t complain) 2911 { 2912 int ref1, i; 2913 int enum_p = 0; 2914 tree type, argtypes[3], t; 2915 /* TYPES[i] is the set of possible builtin-operator parameter types 2916 we will consider for the Ith argument. */ 2917 vec<tree, va_gc> *types[2]; 2918 unsigned ix; 2919 2920 for (i = 0; i < 3; ++i) 2921 { 2922 if (args[i]) 2923 argtypes[i] = unlowered_expr_type (args[i]); 2924 else 2925 argtypes[i] = NULL_TREE; 2926 } 2927 2928 switch (code) 2929 { 2930 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type, 2931 and VQ is either volatile or empty, there exist candidate operator 2932 functions of the form 2933 VQ T& operator++(VQ T&); */ 2934 2935 case POSTINCREMENT_EXPR: 2936 case PREINCREMENT_EXPR: 2937 case POSTDECREMENT_EXPR: 2938 case PREDECREMENT_EXPR: 2939 case MODIFY_EXPR: 2940 ref1 = 1; 2941 break; 2942 2943 /* 24There also exist candidate operator functions of the form 2944 bool operator!(bool); 2945 bool operator&&(bool, bool); 2946 bool operator||(bool, bool); */ 2947 2948 case TRUTH_NOT_EXPR: 2949 build_builtin_candidate 2950 (candidates, fnname, boolean_type_node, 2951 NULL_TREE, args, argtypes, flags, complain); 2952 return; 2953 2954 case TRUTH_ORIF_EXPR: 2955 case TRUTH_ANDIF_EXPR: 2956 build_builtin_candidate 2957 (candidates, fnname, boolean_type_node, 2958 boolean_type_node, args, argtypes, flags, complain); 2959 return; 2960 2961 case ADDR_EXPR: 2962 case COMPOUND_EXPR: 2963 case COMPONENT_REF: 2964 return; 2965 2966 case COND_EXPR: 2967 case EQ_EXPR: 2968 case NE_EXPR: 2969 case LT_EXPR: 2970 case LE_EXPR: 2971 case GT_EXPR: 2972 case GE_EXPR: 2973 enum_p = 1; 2974 /* Fall through. */ 2975 2976 default: 2977 ref1 = 0; 2978 } 2979 2980 types[0] = make_tree_vector (); 2981 types[1] = make_tree_vector (); 2982 2983 for (i = 0; i < 2; ++i) 2984 { 2985 if (! args[i]) 2986 ; 2987 else if (MAYBE_CLASS_TYPE_P (argtypes[i])) 2988 { 2989 tree convs; 2990 2991 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR) 2992 return; 2993 2994 convs = lookup_conversions (argtypes[i]); 2995 2996 if (code == COND_EXPR) 2997 { 2998 if (lvalue_p (args[i])) 2999 vec_safe_push (types[i], build_reference_type (argtypes[i])); 3000 3001 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i])); 3002 } 3003 3004 else if (! convs) 3005 return; 3006 3007 for (; convs; convs = TREE_CHAIN (convs)) 3008 { 3009 type = TREE_TYPE (convs); 3010 3011 if (i == 0 && ref1 3012 && (TREE_CODE (type) != REFERENCE_TYPE 3013 || CP_TYPE_CONST_P (TREE_TYPE (type)))) 3014 continue; 3015 3016 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE) 3017 vec_safe_push (types[i], type); 3018 3019 type = non_reference (type); 3020 if (i != 0 || ! ref1) 3021 { 3022 type = cv_unqualified (type_decays_to (type)); 3023 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE) 3024 vec_safe_push (types[i], type); 3025 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 3026 type = type_promotes_to (type); 3027 } 3028 3029 if (! vec_member (type, types[i])) 3030 vec_safe_push (types[i], type); 3031 } 3032 } 3033 else 3034 { 3035 if (code == COND_EXPR && lvalue_p (args[i])) 3036 vec_safe_push (types[i], build_reference_type (argtypes[i])); 3037 type = non_reference (argtypes[i]); 3038 if (i != 0 || ! ref1) 3039 { 3040 type = cv_unqualified (type_decays_to (type)); 3041 if (enum_p && UNSCOPED_ENUM_P (type)) 3042 vec_safe_push (types[i], type); 3043 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) 3044 type = type_promotes_to (type); 3045 } 3046 vec_safe_push (types[i], type); 3047 } 3048 } 3049 3050 /* Run through the possible parameter types of both arguments, 3051 creating candidates with those parameter types. */ 3052 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t) 3053 { 3054 unsigned jx; 3055 tree u; 3056 3057 if (!types[1]->is_empty ()) 3058 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u) 3059 add_builtin_candidate 3060 (candidates, code, code2, fnname, t, 3061 u, args, argtypes, flags, complain); 3062 else 3063 add_builtin_candidate 3064 (candidates, code, code2, fnname, t, 3065 NULL_TREE, args, argtypes, flags, complain); 3066 } 3067 3068 release_tree_vector (types[0]); 3069 release_tree_vector (types[1]); 3070 } 3071 3072 3073 /* If TMPL can be successfully instantiated as indicated by 3074 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES. 3075 3076 TMPL is the template. EXPLICIT_TARGS are any explicit template 3077 arguments. ARGLIST is the arguments provided at the call-site. 3078 This does not change ARGLIST. The RETURN_TYPE is the desired type 3079 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are 3080 as for add_function_candidate. If an OBJ is supplied, FLAGS and 3081 CTYPE are ignored, and OBJ is as for add_conv_candidate. */ 3082 3083 static struct z_candidate* 3084 add_template_candidate_real (struct z_candidate **candidates, tree tmpl, 3085 tree ctype, tree explicit_targs, tree first_arg, 3086 const vec<tree, va_gc> *arglist, tree return_type, 3087 tree access_path, tree conversion_path, 3088 int flags, tree obj, unification_kind_t strict, 3089 tsubst_flags_t complain) 3090 { 3091 int ntparms = DECL_NTPARMS (tmpl); 3092 tree targs = make_tree_vec (ntparms); 3093 unsigned int len = vec_safe_length (arglist); 3094 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len; 3095 unsigned int skip_without_in_chrg = 0; 3096 tree first_arg_without_in_chrg = first_arg; 3097 tree *args_without_in_chrg; 3098 unsigned int nargs_without_in_chrg; 3099 unsigned int ia, ix; 3100 tree arg; 3101 struct z_candidate *cand; 3102 tree fn; 3103 struct rejection_reason *reason = NULL; 3104 int errs; 3105 3106 /* We don't do deduction on the in-charge parameter, the VTT 3107 parameter or 'this'. */ 3108 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl)) 3109 { 3110 if (first_arg_without_in_chrg != NULL_TREE) 3111 first_arg_without_in_chrg = NULL_TREE; 3112 else if (return_type && strict == DEDUCE_CALL) 3113 /* We're deducing for a call to the result of a template conversion 3114 function, so the args don't contain 'this'; leave them alone. */; 3115 else 3116 ++skip_without_in_chrg; 3117 } 3118 3119 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl) 3120 || DECL_BASE_CONSTRUCTOR_P (tmpl)) 3121 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl))) 3122 { 3123 if (first_arg_without_in_chrg != NULL_TREE) 3124 first_arg_without_in_chrg = NULL_TREE; 3125 else 3126 ++skip_without_in_chrg; 3127 } 3128 3129 if (len < skip_without_in_chrg) 3130 return NULL; 3131 3132 if (DECL_CONSTRUCTOR_P (tmpl) && nargs == 2 3133 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (first_arg), 3134 TREE_TYPE ((*arglist)[0]))) 3135 { 3136 /* 12.8/6 says, "A declaration of a constructor for a class X is 3137 ill-formed if its first parameter is of type (optionally cv-qualified) 3138 X and either there are no other parameters or else all other 3139 parameters have default arguments. A member function template is never 3140 instantiated to produce such a constructor signature." 3141 3142 So if we're trying to copy an object of the containing class, don't 3143 consider a template constructor that has a first parameter type that 3144 is just a template parameter, as we would deduce a signature that we 3145 would then reject in the code below. */ 3146 if (tree firstparm = FUNCTION_FIRST_USER_PARMTYPE (tmpl)) 3147 { 3148 firstparm = TREE_VALUE (firstparm); 3149 if (PACK_EXPANSION_P (firstparm)) 3150 firstparm = PACK_EXPANSION_PATTERN (firstparm); 3151 if (TREE_CODE (firstparm) == TEMPLATE_TYPE_PARM) 3152 { 3153 gcc_assert (!explicit_targs); 3154 reason = invalid_copy_with_fn_template_rejection (); 3155 goto fail; 3156 } 3157 } 3158 } 3159 3160 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0) 3161 + (len - skip_without_in_chrg)); 3162 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg); 3163 ia = 0; 3164 if (first_arg_without_in_chrg != NULL_TREE) 3165 { 3166 args_without_in_chrg[ia] = first_arg_without_in_chrg; 3167 ++ia; 3168 } 3169 for (ix = skip_without_in_chrg; 3170 vec_safe_iterate (arglist, ix, &arg); 3171 ++ix) 3172 { 3173 args_without_in_chrg[ia] = arg; 3174 ++ia; 3175 } 3176 gcc_assert (ia == nargs_without_in_chrg); 3177 3178 errs = errorcount+sorrycount; 3179 fn = fn_type_unification (tmpl, explicit_targs, targs, 3180 args_without_in_chrg, 3181 nargs_without_in_chrg, 3182 return_type, strict, flags, false, 3183 complain & tf_decltype); 3184 3185 if (fn == error_mark_node) 3186 { 3187 /* Don't repeat unification later if it already resulted in errors. */ 3188 if (errorcount+sorrycount == errs) 3189 reason = template_unification_rejection (tmpl, explicit_targs, 3190 targs, args_without_in_chrg, 3191 nargs_without_in_chrg, 3192 return_type, strict, flags); 3193 else 3194 reason = template_unification_error_rejection (); 3195 goto fail; 3196 } 3197 3198 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2) 3199 { 3200 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn); 3201 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)), 3202 ctype)) 3203 { 3204 /* We're trying to produce a constructor with a prohibited signature, 3205 as discussed above; handle here any cases we didn't catch then, 3206 such as X(X<T>). */ 3207 reason = invalid_copy_with_fn_template_rejection (); 3208 goto fail; 3209 } 3210 } 3211 3212 if (obj != NULL_TREE) 3213 /* Aha, this is a conversion function. */ 3214 cand = add_conv_candidate (candidates, fn, obj, arglist, 3215 access_path, conversion_path, complain); 3216 else 3217 cand = add_function_candidate (candidates, fn, ctype, 3218 first_arg, arglist, access_path, 3219 conversion_path, flags, complain); 3220 if (DECL_TI_TEMPLATE (fn) != tmpl) 3221 /* This situation can occur if a member template of a template 3222 class is specialized. Then, instantiate_template might return 3223 an instantiation of the specialization, in which case the 3224 DECL_TI_TEMPLATE field will point at the original 3225 specialization. For example: 3226 3227 template <class T> struct S { template <class U> void f(U); 3228 template <> void f(int) {}; }; 3229 S<double> sd; 3230 sd.f(3); 3231 3232 Here, TMPL will be template <class U> S<double>::f(U). 3233 And, instantiate template will give us the specialization 3234 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field 3235 for this will point at template <class T> template <> S<T>::f(int), 3236 so that we can find the definition. For the purposes of 3237 overload resolution, however, we want the original TMPL. */ 3238 cand->template_decl = build_template_info (tmpl, targs); 3239 else 3240 cand->template_decl = DECL_TEMPLATE_INFO (fn); 3241 cand->explicit_targs = explicit_targs; 3242 3243 return cand; 3244 fail: 3245 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL, 3246 access_path, conversion_path, 0, reason, flags); 3247 } 3248 3249 3250 static struct z_candidate * 3251 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype, 3252 tree explicit_targs, tree first_arg, 3253 const vec<tree, va_gc> *arglist, tree return_type, 3254 tree access_path, tree conversion_path, int flags, 3255 unification_kind_t strict, tsubst_flags_t complain) 3256 { 3257 return 3258 add_template_candidate_real (candidates, tmpl, ctype, 3259 explicit_targs, first_arg, arglist, 3260 return_type, access_path, conversion_path, 3261 flags, NULL_TREE, strict, complain); 3262 } 3263 3264 /* Create an overload candidate for the conversion function template TMPL, 3265 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a 3266 pointer-to-function which will in turn be called with the argument list 3267 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is 3268 passed on to implicit_conversion. */ 3269 3270 static struct z_candidate * 3271 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl, 3272 tree obj, 3273 const vec<tree, va_gc> *arglist, 3274 tree return_type, tree access_path, 3275 tree conversion_path, tsubst_flags_t complain) 3276 { 3277 /* Making this work broke PR 71117 and 85118, so until the committee resolves 3278 core issue 2189, let's disable this candidate if there are any call 3279 operators. */ 3280 if (*candidates) 3281 return NULL; 3282 3283 return 3284 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE, 3285 NULL_TREE, arglist, return_type, access_path, 3286 conversion_path, 0, obj, DEDUCE_CALL, 3287 complain); 3288 } 3289 3290 /* The CANDS are the set of candidates that were considered for 3291 overload resolution. Return the set of viable candidates, or CANDS 3292 if none are viable. If any of the candidates were viable, set 3293 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be 3294 considered viable only if it is strictly viable. */ 3295 3296 static struct z_candidate* 3297 splice_viable (struct z_candidate *cands, 3298 bool strict_p, 3299 bool *any_viable_p) 3300 { 3301 struct z_candidate *viable; 3302 struct z_candidate **last_viable; 3303 struct z_candidate **cand; 3304 bool found_strictly_viable = false; 3305 3306 /* Be strict inside templates, since build_over_call won't actually 3307 do the conversions to get pedwarns. */ 3308 if (processing_template_decl) 3309 strict_p = true; 3310 3311 viable = NULL; 3312 last_viable = &viable; 3313 *any_viable_p = false; 3314 3315 cand = &cands; 3316 while (*cand) 3317 { 3318 struct z_candidate *c = *cand; 3319 if (!strict_p 3320 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL)) 3321 { 3322 /* Be strict in the presence of a viable candidate. Also if 3323 there are template candidates, so that we get deduction errors 3324 for them instead of silently preferring a bad conversion. */ 3325 strict_p = true; 3326 if (viable && !found_strictly_viable) 3327 { 3328 /* Put any spliced near matches back onto the main list so 3329 that we see them if there is no strict match. */ 3330 *any_viable_p = false; 3331 *last_viable = cands; 3332 cands = viable; 3333 viable = NULL; 3334 last_viable = &viable; 3335 } 3336 } 3337 3338 if (strict_p ? c->viable == 1 : c->viable) 3339 { 3340 *last_viable = c; 3341 *cand = c->next; 3342 c->next = NULL; 3343 last_viable = &c->next; 3344 *any_viable_p = true; 3345 if (c->viable == 1) 3346 found_strictly_viable = true; 3347 } 3348 else 3349 cand = &c->next; 3350 } 3351 3352 return viable ? viable : cands; 3353 } 3354 3355 static bool 3356 any_strictly_viable (struct z_candidate *cands) 3357 { 3358 for (; cands; cands = cands->next) 3359 if (cands->viable == 1) 3360 return true; 3361 return false; 3362 } 3363 3364 /* OBJ is being used in an expression like "OBJ.f (...)". In other 3365 words, it is about to become the "this" pointer for a member 3366 function call. Take the address of the object. */ 3367 3368 static tree 3369 build_this (tree obj) 3370 { 3371 /* In a template, we are only concerned about the type of the 3372 expression, so we can take a shortcut. */ 3373 if (processing_template_decl) 3374 return build_address (obj); 3375 3376 return cp_build_addr_expr (obj, tf_warning_or_error); 3377 } 3378 3379 /* Returns true iff functions are equivalent. Equivalent functions are 3380 not '==' only if one is a function-local extern function or if 3381 both are extern "C". */ 3382 3383 static inline int 3384 equal_functions (tree fn1, tree fn2) 3385 { 3386 if (TREE_CODE (fn1) != TREE_CODE (fn2)) 3387 return 0; 3388 if (TREE_CODE (fn1) == TEMPLATE_DECL) 3389 return fn1 == fn2; 3390 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2) 3391 || DECL_EXTERN_C_FUNCTION_P (fn1)) 3392 return decls_match (fn1, fn2); 3393 return fn1 == fn2; 3394 } 3395 3396 /* Print information about a candidate being rejected due to INFO. */ 3397 3398 static void 3399 print_conversion_rejection (location_t loc, struct conversion_info *info) 3400 { 3401 tree from = info->from; 3402 if (!TYPE_P (from)) 3403 from = lvalue_type (from); 3404 if (info->n_arg == -1) 3405 { 3406 /* Conversion of implicit `this' argument failed. */ 3407 if (!TYPE_P (info->from)) 3408 /* A bad conversion for 'this' must be discarding cv-quals. */ 3409 inform (loc, " passing %qT as %<this%> " 3410 "argument discards qualifiers", 3411 from); 3412 else 3413 inform (loc, " no known conversion for implicit " 3414 "%<this%> parameter from %qH to %qI", 3415 from, info->to_type); 3416 } 3417 else if (!TYPE_P (info->from)) 3418 { 3419 if (info->n_arg >= 0) 3420 inform (loc, " conversion of argument %d would be ill-formed:", 3421 info->n_arg + 1); 3422 perform_implicit_conversion (info->to_type, info->from, 3423 tf_warning_or_error); 3424 } 3425 else if (info->n_arg == -2) 3426 /* Conversion of conversion function return value failed. */ 3427 inform (loc, " no known conversion from %qH to %qI", 3428 from, info->to_type); 3429 else 3430 inform (loc, " no known conversion for argument %d from %qH to %qI", 3431 info->n_arg + 1, from, info->to_type); 3432 } 3433 3434 /* Print information about a candidate with WANT parameters and we found 3435 HAVE. */ 3436 3437 static void 3438 print_arity_information (location_t loc, unsigned int have, unsigned int want) 3439 { 3440 inform_n (loc, want, 3441 " candidate expects %d argument, %d provided", 3442 " candidate expects %d arguments, %d provided", 3443 want, have); 3444 } 3445 3446 /* Print information about one overload candidate CANDIDATE. MSGSTR 3447 is the text to print before the candidate itself. 3448 3449 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected 3450 to have been run through gettext by the caller. This wart makes 3451 life simpler in print_z_candidates and for the translators. */ 3452 3453 static void 3454 print_z_candidate (location_t loc, const char *msgstr, 3455 struct z_candidate *candidate) 3456 { 3457 const char *msg = (msgstr == NULL 3458 ? "" 3459 : ACONCAT ((msgstr, " ", NULL))); 3460 tree fn = candidate->fn; 3461 if (flag_new_inheriting_ctors) 3462 fn = strip_inheriting_ctors (fn); 3463 location_t cloc = location_of (fn); 3464 3465 if (identifier_p (fn)) 3466 { 3467 cloc = loc; 3468 if (candidate->num_convs == 3) 3469 inform (cloc, "%s%<%D(%T, %T, %T)%> <built-in>", msg, fn, 3470 candidate->convs[0]->type, 3471 candidate->convs[1]->type, 3472 candidate->convs[2]->type); 3473 else if (candidate->num_convs == 2) 3474 inform (cloc, "%s%<%D(%T, %T)%> <built-in>", msg, fn, 3475 candidate->convs[0]->type, 3476 candidate->convs[1]->type); 3477 else 3478 inform (cloc, "%s%<%D(%T)%> <built-in>", msg, fn, 3479 candidate->convs[0]->type); 3480 } 3481 else if (TYPE_P (fn)) 3482 inform (cloc, "%s%qT <conversion>", msg, fn); 3483 else if (candidate->viable == -1) 3484 inform (cloc, "%s%#qD <near match>", msg, fn); 3485 else if (DECL_DELETED_FN (fn)) 3486 inform (cloc, "%s%#qD <deleted>", msg, fn); 3487 else 3488 inform (cloc, "%s%#qD", msg, fn); 3489 if (fn != candidate->fn) 3490 { 3491 cloc = location_of (candidate->fn); 3492 inform (cloc, " inherited here"); 3493 } 3494 /* Give the user some information about why this candidate failed. */ 3495 if (candidate->reason != NULL) 3496 { 3497 struct rejection_reason *r = candidate->reason; 3498 3499 switch (r->code) 3500 { 3501 case rr_arity: 3502 print_arity_information (cloc, r->u.arity.actual, 3503 r->u.arity.expected); 3504 break; 3505 case rr_arg_conversion: 3506 print_conversion_rejection (cloc, &r->u.conversion); 3507 break; 3508 case rr_bad_arg_conversion: 3509 print_conversion_rejection (cloc, &r->u.bad_conversion); 3510 break; 3511 case rr_explicit_conversion: 3512 inform (cloc, " return type %qT of explicit conversion function " 3513 "cannot be converted to %qT with a qualification " 3514 "conversion", r->u.conversion.from, 3515 r->u.conversion.to_type); 3516 break; 3517 case rr_template_conversion: 3518 inform (cloc, " conversion from return type %qT of template " 3519 "conversion function specialization to %qT is not an " 3520 "exact match", r->u.conversion.from, 3521 r->u.conversion.to_type); 3522 break; 3523 case rr_template_unification: 3524 /* We use template_unification_error_rejection if unification caused 3525 actual non-SFINAE errors, in which case we don't need to repeat 3526 them here. */ 3527 if (r->u.template_unification.tmpl == NULL_TREE) 3528 { 3529 inform (cloc, " substitution of deduced template arguments " 3530 "resulted in errors seen above"); 3531 break; 3532 } 3533 /* Re-run template unification with diagnostics. */ 3534 inform (cloc, " template argument deduction/substitution failed:"); 3535 fn_type_unification (r->u.template_unification.tmpl, 3536 r->u.template_unification.explicit_targs, 3537 (make_tree_vec 3538 (r->u.template_unification.num_targs)), 3539 r->u.template_unification.args, 3540 r->u.template_unification.nargs, 3541 r->u.template_unification.return_type, 3542 r->u.template_unification.strict, 3543 r->u.template_unification.flags, 3544 true, false); 3545 break; 3546 case rr_invalid_copy: 3547 inform (cloc, 3548 " a constructor taking a single argument of its own " 3549 "class type is invalid"); 3550 break; 3551 case rr_constraint_failure: 3552 { 3553 tree tmpl = r->u.template_instantiation.tmpl; 3554 tree args = r->u.template_instantiation.targs; 3555 diagnose_constraints (cloc, tmpl, args); 3556 } 3557 break; 3558 case rr_inherited_ctor: 3559 inform (cloc, " an inherited constructor is not a candidate for " 3560 "initialization from an expression of the same or derived " 3561 "type"); 3562 break; 3563 case rr_none: 3564 default: 3565 /* This candidate didn't have any issues or we failed to 3566 handle a particular code. Either way... */ 3567 gcc_unreachable (); 3568 } 3569 } 3570 } 3571 3572 static void 3573 print_z_candidates (location_t loc, struct z_candidate *candidates) 3574 { 3575 struct z_candidate *cand1; 3576 struct z_candidate **cand2; 3577 3578 if (!candidates) 3579 return; 3580 3581 /* Remove non-viable deleted candidates. */ 3582 cand1 = candidates; 3583 for (cand2 = &cand1; *cand2; ) 3584 { 3585 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL 3586 && !(*cand2)->viable 3587 && DECL_DELETED_FN ((*cand2)->fn)) 3588 *cand2 = (*cand2)->next; 3589 else 3590 cand2 = &(*cand2)->next; 3591 } 3592 /* ...if there are any non-deleted ones. */ 3593 if (cand1) 3594 candidates = cand1; 3595 3596 /* There may be duplicates in the set of candidates. We put off 3597 checking this condition as long as possible, since we have no way 3598 to eliminate duplicates from a set of functions in less than n^2 3599 time. Now we are about to emit an error message, so it is more 3600 permissible to go slowly. */ 3601 for (cand1 = candidates; cand1; cand1 = cand1->next) 3602 { 3603 tree fn = cand1->fn; 3604 /* Skip builtin candidates and conversion functions. */ 3605 if (!DECL_P (fn)) 3606 continue; 3607 cand2 = &cand1->next; 3608 while (*cand2) 3609 { 3610 if (DECL_P ((*cand2)->fn) 3611 && equal_functions (fn, (*cand2)->fn)) 3612 *cand2 = (*cand2)->next; 3613 else 3614 cand2 = &(*cand2)->next; 3615 } 3616 } 3617 3618 for (; candidates; candidates = candidates->next) 3619 print_z_candidate (loc, "candidate:", candidates); 3620 } 3621 3622 /* USER_SEQ is a user-defined conversion sequence, beginning with a 3623 USER_CONV. STD_SEQ is the standard conversion sequence applied to 3624 the result of the conversion function to convert it to the final 3625 desired type. Merge the two sequences into a single sequence, 3626 and return the merged sequence. */ 3627 3628 static conversion * 3629 merge_conversion_sequences (conversion *user_seq, conversion *std_seq) 3630 { 3631 conversion **t; 3632 bool bad = user_seq->bad_p; 3633 3634 gcc_assert (user_seq->kind == ck_user); 3635 3636 /* Find the end of the second conversion sequence. */ 3637 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next)) 3638 { 3639 /* The entire sequence is a user-conversion sequence. */ 3640 (*t)->user_conv_p = true; 3641 if (bad) 3642 (*t)->bad_p = true; 3643 } 3644 3645 if ((*t)->rvaluedness_matches_p) 3646 /* We're binding a reference directly to the result of the conversion. 3647 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return 3648 type, but we want it back. */ 3649 user_seq->type = TREE_TYPE (TREE_TYPE (user_seq->cand->fn)); 3650 3651 /* Replace the identity conversion with the user conversion 3652 sequence. */ 3653 *t = user_seq; 3654 3655 return std_seq; 3656 } 3657 3658 /* Handle overload resolution for initializing an object of class type from 3659 an initializer list. First we look for a suitable constructor that 3660 takes a std::initializer_list; if we don't find one, we then look for a 3661 non-list constructor. 3662 3663 Parameters are as for add_candidates, except that the arguments are in 3664 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and 3665 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */ 3666 3667 static void 3668 add_list_candidates (tree fns, tree first_arg, 3669 const vec<tree, va_gc> *args, tree totype, 3670 tree explicit_targs, bool template_only, 3671 tree conversion_path, tree access_path, 3672 int flags, 3673 struct z_candidate **candidates, 3674 tsubst_flags_t complain) 3675 { 3676 gcc_assert (*candidates == NULL); 3677 3678 /* We're looking for a ctor for list-initialization. */ 3679 flags |= LOOKUP_LIST_INIT_CTOR; 3680 /* And we don't allow narrowing conversions. We also use this flag to 3681 avoid the copy constructor call for copy-list-initialization. */ 3682 flags |= LOOKUP_NO_NARROWING; 3683 3684 unsigned nart = num_artificial_parms_for (OVL_FIRST (fns)) - 1; 3685 tree init_list = (*args)[nart]; 3686 3687 /* Always use the default constructor if the list is empty (DR 990). */ 3688 if (CONSTRUCTOR_NELTS (init_list) == 0 3689 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 3690 ; 3691 /* If the class has a list ctor, try passing the list as a single 3692 argument first, but only consider list ctors. */ 3693 else if (TYPE_HAS_LIST_CTOR (totype)) 3694 { 3695 flags |= LOOKUP_LIST_ONLY; 3696 add_candidates (fns, first_arg, args, NULL_TREE, 3697 explicit_targs, template_only, conversion_path, 3698 access_path, flags, candidates, complain); 3699 if (any_strictly_viable (*candidates)) 3700 return; 3701 } 3702 3703 /* Expand the CONSTRUCTOR into a new argument vec. */ 3704 vec<tree, va_gc> *new_args; 3705 vec_alloc (new_args, nart + CONSTRUCTOR_NELTS (init_list)); 3706 for (unsigned i = 0; i < nart; ++i) 3707 new_args->quick_push ((*args)[i]); 3708 for (unsigned i = 0; i < CONSTRUCTOR_NELTS (init_list); ++i) 3709 new_args->quick_push (CONSTRUCTOR_ELT (init_list, i)->value); 3710 3711 /* We aren't looking for list-ctors anymore. */ 3712 flags &= ~LOOKUP_LIST_ONLY; 3713 /* We allow more user-defined conversions within an init-list. */ 3714 flags &= ~LOOKUP_NO_CONVERSION; 3715 3716 add_candidates (fns, first_arg, new_args, NULL_TREE, 3717 explicit_targs, template_only, conversion_path, 3718 access_path, flags, candidates, complain); 3719 } 3720 3721 /* Returns the best overload candidate to perform the requested 3722 conversion. This function is used for three the overloading situations 3723 described in [over.match.copy], [over.match.conv], and [over.match.ref]. 3724 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as 3725 per [dcl.init.ref], so we ignore temporary bindings. */ 3726 3727 static struct z_candidate * 3728 build_user_type_conversion_1 (tree totype, tree expr, int flags, 3729 tsubst_flags_t complain) 3730 { 3731 struct z_candidate *candidates, *cand; 3732 tree fromtype; 3733 tree ctors = NULL_TREE; 3734 tree conv_fns = NULL_TREE; 3735 conversion *conv = NULL; 3736 tree first_arg = NULL_TREE; 3737 vec<tree, va_gc> *args = NULL; 3738 bool any_viable_p; 3739 int convflags; 3740 3741 if (!expr) 3742 return NULL; 3743 3744 fromtype = TREE_TYPE (expr); 3745 3746 /* We represent conversion within a hierarchy using RVALUE_CONV and 3747 BASE_CONV, as specified by [over.best.ics]; these become plain 3748 constructor calls, as specified in [dcl.init]. */ 3749 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype) 3750 || !DERIVED_FROM_P (totype, fromtype)); 3751 3752 if (CLASS_TYPE_P (totype)) 3753 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid 3754 creating a garbage BASELINK; constructors can't be inherited. */ 3755 ctors = get_class_binding (totype, complete_ctor_identifier); 3756 3757 if (MAYBE_CLASS_TYPE_P (fromtype)) 3758 { 3759 tree to_nonref = non_reference (totype); 3760 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) || 3761 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype) 3762 && DERIVED_FROM_P (to_nonref, fromtype))) 3763 { 3764 /* [class.conv.fct] A conversion function is never used to 3765 convert a (possibly cv-qualified) object to the (possibly 3766 cv-qualified) same object type (or a reference to it), to a 3767 (possibly cv-qualified) base class of that type (or a 3768 reference to it)... */ 3769 } 3770 else 3771 conv_fns = lookup_conversions (fromtype); 3772 } 3773 3774 candidates = 0; 3775 flags |= LOOKUP_NO_CONVERSION; 3776 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3777 flags |= LOOKUP_NO_NARROWING; 3778 3779 /* It's OK to bind a temporary for converting constructor arguments, but 3780 not in converting the return value of a conversion operator. */ 3781 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION 3782 | (flags & LOOKUP_NO_NARROWING)); 3783 flags &= ~LOOKUP_NO_TEMP_BIND; 3784 3785 if (ctors) 3786 { 3787 int ctorflags = flags; 3788 3789 first_arg = build_dummy_object (totype); 3790 3791 /* We should never try to call the abstract or base constructor 3792 from here. */ 3793 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_FIRST (ctors)) 3794 && !DECL_HAS_VTT_PARM_P (OVL_FIRST (ctors))); 3795 3796 args = make_tree_vector_single (expr); 3797 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3798 { 3799 /* List-initialization. */ 3800 add_list_candidates (ctors, first_arg, args, totype, NULL_TREE, 3801 false, TYPE_BINFO (totype), TYPE_BINFO (totype), 3802 ctorflags, &candidates, complain); 3803 } 3804 else 3805 { 3806 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false, 3807 TYPE_BINFO (totype), TYPE_BINFO (totype), 3808 ctorflags, &candidates, complain); 3809 } 3810 3811 for (cand = candidates; cand; cand = cand->next) 3812 { 3813 cand->second_conv = build_identity_conv (totype, NULL_TREE); 3814 3815 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't 3816 set, then this is copy-initialization. In that case, "The 3817 result of the call is then used to direct-initialize the 3818 object that is the destination of the copy-initialization." 3819 [dcl.init] 3820 3821 We represent this in the conversion sequence with an 3822 rvalue conversion, which means a constructor call. */ 3823 if (TREE_CODE (totype) != REFERENCE_TYPE 3824 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3825 cand->second_conv 3826 = build_conv (ck_rvalue, totype, cand->second_conv); 3827 } 3828 } 3829 3830 if (conv_fns) 3831 { 3832 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 3833 first_arg = CONSTRUCTOR_ELT (expr, 0)->value; 3834 else 3835 first_arg = expr; 3836 } 3837 3838 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns)) 3839 { 3840 tree conversion_path = TREE_PURPOSE (conv_fns); 3841 struct z_candidate *old_candidates; 3842 3843 /* If we are called to convert to a reference type, we are trying to 3844 find a direct binding, so don't even consider temporaries. If 3845 we don't find a direct binding, the caller will try again to 3846 look for a temporary binding. */ 3847 if (TREE_CODE (totype) == REFERENCE_TYPE) 3848 convflags |= LOOKUP_NO_TEMP_BIND; 3849 3850 old_candidates = candidates; 3851 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype, 3852 NULL_TREE, false, 3853 conversion_path, TYPE_BINFO (fromtype), 3854 flags, &candidates, complain); 3855 3856 for (cand = candidates; cand != old_candidates; cand = cand->next) 3857 { 3858 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn)); 3859 conversion *ics 3860 = implicit_conversion (totype, 3861 rettype, 3862 0, 3863 /*c_cast_p=*/false, convflags, 3864 complain); 3865 3866 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is 3867 copy-initialization. In that case, "The result of the 3868 call is then used to direct-initialize the object that is 3869 the destination of the copy-initialization." [dcl.init] 3870 3871 We represent this in the conversion sequence with an 3872 rvalue conversion, which means a constructor call. But 3873 don't add a second rvalue conversion if there's already 3874 one there. Which there really shouldn't be, but it's 3875 harmless since we'd add it here anyway. */ 3876 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue 3877 && !(convflags & LOOKUP_NO_TEMP_BIND)) 3878 ics = build_conv (ck_rvalue, totype, ics); 3879 3880 cand->second_conv = ics; 3881 3882 if (!ics) 3883 { 3884 cand->viable = 0; 3885 cand->reason = arg_conversion_rejection (NULL_TREE, -2, 3886 rettype, totype); 3887 } 3888 else if (DECL_NONCONVERTING_P (cand->fn) 3889 && ics->rank > cr_exact) 3890 { 3891 /* 13.3.1.5: For direct-initialization, those explicit 3892 conversion functions that are not hidden within S and 3893 yield type T or a type that can be converted to type T 3894 with a qualification conversion (4.4) are also candidate 3895 functions. */ 3896 /* 13.3.1.6 doesn't have a parallel restriction, but it should; 3897 I've raised this issue with the committee. --jason 9/2011 */ 3898 cand->viable = -1; 3899 cand->reason = explicit_conversion_rejection (rettype, totype); 3900 } 3901 else if (cand->viable == 1 && ics->bad_p) 3902 { 3903 cand->viable = -1; 3904 cand->reason 3905 = bad_arg_conversion_rejection (NULL_TREE, -2, 3906 rettype, totype); 3907 } 3908 else if (primary_template_specialization_p (cand->fn) 3909 && ics->rank > cr_exact) 3910 { 3911 /* 13.3.3.1.2: If the user-defined conversion is specified by 3912 a specialization of a conversion function template, the 3913 second standard conversion sequence shall have exact match 3914 rank. */ 3915 cand->viable = -1; 3916 cand->reason = template_conversion_rejection (rettype, totype); 3917 } 3918 } 3919 } 3920 3921 candidates = splice_viable (candidates, false, &any_viable_p); 3922 if (!any_viable_p) 3923 { 3924 if (args) 3925 release_tree_vector (args); 3926 return NULL; 3927 } 3928 3929 cand = tourney (candidates, complain); 3930 if (cand == 0) 3931 { 3932 if (complain & tf_error) 3933 { 3934 error ("conversion from %qH to %qI is ambiguous", 3935 fromtype, totype); 3936 print_z_candidates (location_of (expr), candidates); 3937 } 3938 3939 cand = candidates; /* any one will do */ 3940 cand->second_conv = build_ambiguous_conv (totype, expr); 3941 cand->second_conv->user_conv_p = true; 3942 if (!any_strictly_viable (candidates)) 3943 cand->second_conv->bad_p = true; 3944 if (flags & LOOKUP_ONLYCONVERTING) 3945 cand->second_conv->need_temporary_p = true; 3946 /* If there are viable candidates, don't set ICS_BAD_FLAG; an 3947 ambiguous conversion is no worse than another user-defined 3948 conversion. */ 3949 3950 return cand; 3951 } 3952 3953 tree convtype; 3954 if (!DECL_CONSTRUCTOR_P (cand->fn)) 3955 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn))); 3956 else if (cand->second_conv->kind == ck_rvalue) 3957 /* DR 5: [in the first step of copy-initialization]...if the function 3958 is a constructor, the call initializes a temporary of the 3959 cv-unqualified version of the destination type. */ 3960 convtype = cv_unqualified (totype); 3961 else 3962 convtype = totype; 3963 /* Build the user conversion sequence. */ 3964 conv = build_conv 3965 (ck_user, 3966 convtype, 3967 build_identity_conv (TREE_TYPE (expr), expr)); 3968 conv->cand = cand; 3969 if (cand->viable == -1) 3970 conv->bad_p = true; 3971 3972 /* Remember that this was a list-initialization. */ 3973 if (flags & LOOKUP_NO_NARROWING) 3974 conv->check_narrowing = true; 3975 3976 /* Combine it with the second conversion sequence. */ 3977 cand->second_conv = merge_conversion_sequences (conv, 3978 cand->second_conv); 3979 3980 return cand; 3981 } 3982 3983 /* Wrapper for above. */ 3984 3985 tree 3986 build_user_type_conversion (tree totype, tree expr, int flags, 3987 tsubst_flags_t complain) 3988 { 3989 struct z_candidate *cand; 3990 tree ret; 3991 3992 bool subtime = timevar_cond_start (TV_OVERLOAD); 3993 cand = build_user_type_conversion_1 (totype, expr, flags, complain); 3994 3995 if (cand) 3996 { 3997 if (cand->second_conv->kind == ck_ambig) 3998 ret = error_mark_node; 3999 else 4000 { 4001 expr = convert_like (cand->second_conv, expr, complain); 4002 ret = convert_from_reference (expr); 4003 } 4004 } 4005 else 4006 ret = NULL_TREE; 4007 4008 timevar_cond_stop (TV_OVERLOAD, subtime); 4009 return ret; 4010 } 4011 4012 /* Subroutine of convert_nontype_argument. 4013 4014 EXPR is an expression used in a context that requires a converted 4015 constant-expression, such as a template non-type parameter. Do any 4016 necessary conversions (that are permitted for converted 4017 constant-expressions) to convert it to the desired type. 4018 4019 If conversion is successful, returns the converted expression; 4020 otherwise, returns error_mark_node. */ 4021 4022 tree 4023 build_converted_constant_expr (tree type, tree expr, tsubst_flags_t complain) 4024 { 4025 conversion *conv; 4026 void *p; 4027 tree t; 4028 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 4029 4030 if (error_operand_p (expr)) 4031 return error_mark_node; 4032 4033 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4034 p = conversion_obstack_alloc (0); 4035 4036 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 4037 /*c_cast_p=*/false, 4038 LOOKUP_IMPLICIT, complain); 4039 4040 /* A converted constant expression of type T is an expression, implicitly 4041 converted to type T, where the converted expression is a constant 4042 expression and the implicit conversion sequence contains only 4043 4044 * user-defined conversions, 4045 * lvalue-to-rvalue conversions (7.1), 4046 * array-to-pointer conversions (7.2), 4047 * function-to-pointer conversions (7.3), 4048 * qualification conversions (7.5), 4049 * integral promotions (7.6), 4050 * integral conversions (7.8) other than narrowing conversions (11.6.4), 4051 * null pointer conversions (7.11) from std::nullptr_t, 4052 * null member pointer conversions (7.12) from std::nullptr_t, and 4053 * function pointer conversions (7.13), 4054 4055 and where the reference binding (if any) binds directly. */ 4056 4057 for (conversion *c = conv; 4058 conv && c->kind != ck_identity; 4059 c = next_conversion (c)) 4060 { 4061 switch (c->kind) 4062 { 4063 /* A conversion function is OK. If it isn't constexpr, we'll 4064 complain later that the argument isn't constant. */ 4065 case ck_user: 4066 /* The lvalue-to-rvalue conversion is OK. */ 4067 case ck_rvalue: 4068 /* Array-to-pointer and function-to-pointer. */ 4069 case ck_lvalue: 4070 /* Function pointer conversions. */ 4071 case ck_fnptr: 4072 /* Qualification conversions. */ 4073 case ck_qual: 4074 break; 4075 4076 case ck_ref_bind: 4077 if (c->need_temporary_p) 4078 { 4079 if (complain & tf_error) 4080 error_at (loc, "initializing %qH with %qI in converted " 4081 "constant expression does not bind directly", 4082 type, next_conversion (c)->type); 4083 conv = NULL; 4084 } 4085 break; 4086 4087 case ck_base: 4088 case ck_pmem: 4089 case ck_ptr: 4090 case ck_std: 4091 t = next_conversion (c)->type; 4092 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t) 4093 && INTEGRAL_OR_ENUMERATION_TYPE_P (type)) 4094 /* Integral promotion or conversion. */ 4095 break; 4096 if (NULLPTR_TYPE_P (t)) 4097 /* Conversion from nullptr to pointer or pointer-to-member. */ 4098 break; 4099 4100 if (complain & tf_error) 4101 error_at (loc, "conversion from %qH to %qI in a " 4102 "converted constant expression", t, type); 4103 /* fall through. */ 4104 4105 default: 4106 conv = NULL; 4107 break; 4108 } 4109 } 4110 4111 /* Avoid confusing convert_nontype_argument by introducing 4112 a redundant conversion to the same reference type. */ 4113 if (conv && conv->kind == ck_ref_bind 4114 && REFERENCE_REF_P (expr)) 4115 { 4116 tree ref = TREE_OPERAND (expr, 0); 4117 if (same_type_p (type, TREE_TYPE (ref))) 4118 return ref; 4119 } 4120 4121 if (conv) 4122 expr = convert_like (conv, expr, complain); 4123 else 4124 expr = error_mark_node; 4125 4126 /* Free all the conversions we allocated. */ 4127 obstack_free (&conversion_obstack, p); 4128 4129 return expr; 4130 } 4131 4132 /* Do any initial processing on the arguments to a function call. */ 4133 4134 static vec<tree, va_gc> * 4135 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain) 4136 { 4137 unsigned int ix; 4138 tree arg; 4139 4140 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 4141 { 4142 if (error_operand_p (arg)) 4143 return NULL; 4144 else if (VOID_TYPE_P (TREE_TYPE (arg))) 4145 { 4146 if (complain & tf_error) 4147 error ("invalid use of void expression"); 4148 return NULL; 4149 } 4150 else if (invalid_nonstatic_memfn_p (input_location, arg, complain)) 4151 return NULL; 4152 } 4153 return args; 4154 } 4155 4156 /* Perform overload resolution on FN, which is called with the ARGS. 4157 4158 Return the candidate function selected by overload resolution, or 4159 NULL if the event that overload resolution failed. In the case 4160 that overload resolution fails, *CANDIDATES will be the set of 4161 candidates considered, and ANY_VIABLE_P will be set to true or 4162 false to indicate whether or not any of the candidates were 4163 viable. 4164 4165 The ARGS should already have gone through RESOLVE_ARGS before this 4166 function is called. */ 4167 4168 static struct z_candidate * 4169 perform_overload_resolution (tree fn, 4170 const vec<tree, va_gc> *args, 4171 struct z_candidate **candidates, 4172 bool *any_viable_p, tsubst_flags_t complain) 4173 { 4174 struct z_candidate *cand; 4175 tree explicit_targs; 4176 int template_only; 4177 4178 bool subtime = timevar_cond_start (TV_OVERLOAD); 4179 4180 explicit_targs = NULL_TREE; 4181 template_only = 0; 4182 4183 *candidates = NULL; 4184 *any_viable_p = true; 4185 4186 /* Check FN. */ 4187 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 4188 || TREE_CODE (fn) == TEMPLATE_DECL 4189 || TREE_CODE (fn) == OVERLOAD 4190 || TREE_CODE (fn) == TEMPLATE_ID_EXPR); 4191 4192 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4193 { 4194 explicit_targs = TREE_OPERAND (fn, 1); 4195 fn = TREE_OPERAND (fn, 0); 4196 template_only = 1; 4197 } 4198 4199 /* Add the various candidate functions. */ 4200 add_candidates (fn, NULL_TREE, args, NULL_TREE, 4201 explicit_targs, template_only, 4202 /*conversion_path=*/NULL_TREE, 4203 /*access_path=*/NULL_TREE, 4204 LOOKUP_NORMAL, 4205 candidates, complain); 4206 4207 *candidates = splice_viable (*candidates, false, any_viable_p); 4208 if (*any_viable_p) 4209 cand = tourney (*candidates, complain); 4210 else 4211 cand = NULL; 4212 4213 timevar_cond_stop (TV_OVERLOAD, subtime); 4214 return cand; 4215 } 4216 4217 /* Print an error message about being unable to build a call to FN with 4218 ARGS. ANY_VIABLE_P indicates whether any candidate functions could 4219 be located; CANDIDATES is a possibly empty list of such 4220 functions. */ 4221 4222 static void 4223 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args, 4224 struct z_candidate *candidates) 4225 { 4226 tree targs = NULL_TREE; 4227 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4228 { 4229 targs = TREE_OPERAND (fn, 1); 4230 fn = TREE_OPERAND (fn, 0); 4231 } 4232 tree name = OVL_NAME (fn); 4233 location_t loc = location_of (name); 4234 if (targs) 4235 name = lookup_template_function (name, targs); 4236 4237 if (!any_strictly_viable (candidates)) 4238 error_at (loc, "no matching function for call to %<%D(%A)%>", 4239 name, build_tree_list_vec (args)); 4240 else 4241 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous", 4242 name, build_tree_list_vec (args)); 4243 if (candidates) 4244 print_z_candidates (loc, candidates); 4245 } 4246 4247 /* Return an expression for a call to FN (a namespace-scope function, 4248 or a static member function) with the ARGS. This may change 4249 ARGS. */ 4250 4251 tree 4252 build_new_function_call (tree fn, vec<tree, va_gc> **args, 4253 tsubst_flags_t complain) 4254 { 4255 struct z_candidate *candidates, *cand; 4256 bool any_viable_p; 4257 void *p; 4258 tree result; 4259 4260 if (args != NULL && *args != NULL) 4261 { 4262 *args = resolve_args (*args, complain); 4263 if (*args == NULL) 4264 return error_mark_node; 4265 } 4266 4267 if (flag_tm) 4268 tm_malloc_replacement (fn); 4269 4270 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4271 p = conversion_obstack_alloc (0); 4272 4273 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p, 4274 complain); 4275 4276 if (!cand) 4277 { 4278 if (complain & tf_error) 4279 { 4280 // If there is a single (non-viable) function candidate, 4281 // let the error be diagnosed by cp_build_function_call_vec. 4282 if (!any_viable_p && candidates && ! candidates->next 4283 && (TREE_CODE (candidates->fn) == FUNCTION_DECL)) 4284 return cp_build_function_call_vec (candidates->fn, args, complain); 4285 4286 // Otherwise, emit notes for non-viable candidates. 4287 print_error_for_call_failure (fn, *args, candidates); 4288 } 4289 result = error_mark_node; 4290 } 4291 else 4292 { 4293 int flags = LOOKUP_NORMAL; 4294 /* If fn is template_id_expr, the call has explicit template arguments 4295 (e.g. func<int>(5)), communicate this info to build_over_call 4296 through flags so that later we can use it to decide whether to warn 4297 about peculiar null pointer conversion. */ 4298 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR) 4299 { 4300 /* If overload resolution selects a specialization of a 4301 function concept for non-dependent template arguments, 4302 the expression is true if the constraints are satisfied 4303 and false otherwise. 4304 4305 NOTE: This is an extension of Concepts Lite TS that 4306 allows constraints to be used in expressions. */ 4307 if (flag_concepts && !processing_template_decl) 4308 { 4309 tree tmpl = DECL_TI_TEMPLATE (cand->fn); 4310 tree targs = DECL_TI_ARGS (cand->fn); 4311 tree decl = DECL_TEMPLATE_RESULT (tmpl); 4312 if (DECL_DECLARED_CONCEPT_P (decl)) 4313 return evaluate_function_concept (decl, targs); 4314 } 4315 4316 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 4317 } 4318 4319 result = build_over_call (cand, flags, complain); 4320 } 4321 4322 /* Free all the conversions we allocated. */ 4323 obstack_free (&conversion_obstack, p); 4324 4325 return result; 4326 } 4327 4328 /* Build a call to a global operator new. FNNAME is the name of the 4329 operator (either "operator new" or "operator new[]") and ARGS are 4330 the arguments provided. This may change ARGS. *SIZE points to the 4331 total number of bytes required by the allocation, and is updated if 4332 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should 4333 be used. If this function determines that no cookie should be 4334 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK 4335 is not NULL_TREE, it is evaluated before calculating the final 4336 array size, and if it fails, the array size is replaced with 4337 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN 4338 is non-NULL, it will be set, upon return, to the allocation 4339 function called. */ 4340 4341 tree 4342 build_operator_new_call (tree fnname, vec<tree, va_gc> **args, 4343 tree *size, tree *cookie_size, 4344 tree align_arg, tree size_check, 4345 tree *fn, tsubst_flags_t complain) 4346 { 4347 tree original_size = *size; 4348 tree fns; 4349 struct z_candidate *candidates; 4350 struct z_candidate *cand = NULL; 4351 bool any_viable_p; 4352 4353 if (fn) 4354 *fn = NULL_TREE; 4355 /* Set to (size_t)-1 if the size check fails. */ 4356 if (size_check != NULL_TREE) 4357 { 4358 tree errval = TYPE_MAX_VALUE (sizetype); 4359 if (cxx_dialect >= cxx11 && flag_exceptions) 4360 errval = throw_bad_array_new_length (); 4361 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4362 original_size, errval); 4363 } 4364 vec_safe_insert (*args, 0, *size); 4365 *args = resolve_args (*args, complain); 4366 if (*args == NULL) 4367 return error_mark_node; 4368 4369 /* Based on: 4370 4371 [expr.new] 4372 4373 If this lookup fails to find the name, or if the allocated type 4374 is not a class type, the allocation function's name is looked 4375 up in the global scope. 4376 4377 we disregard block-scope declarations of "operator new". */ 4378 fns = lookup_name_real (fnname, 0, 1, /*block_p=*/false, 0, 0); 4379 fns = lookup_arg_dependent (fnname, fns, *args); 4380 4381 if (align_arg) 4382 { 4383 vec<tree, va_gc>* align_args 4384 = vec_copy_and_insert (*args, align_arg, 1); 4385 cand = perform_overload_resolution (fns, align_args, &candidates, 4386 &any_viable_p, tf_none); 4387 if (cand) 4388 *args = align_args; 4389 /* If no aligned allocation function matches, try again without the 4390 alignment. */ 4391 } 4392 4393 /* Figure out what function is being called. */ 4394 if (!cand) 4395 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p, 4396 complain); 4397 4398 /* If no suitable function could be found, issue an error message 4399 and give up. */ 4400 if (!cand) 4401 { 4402 if (complain & tf_error) 4403 print_error_for_call_failure (fns, *args, candidates); 4404 return error_mark_node; 4405 } 4406 4407 /* If a cookie is required, add some extra space. Whether 4408 or not a cookie is required cannot be determined until 4409 after we know which function was called. */ 4410 if (*cookie_size) 4411 { 4412 bool use_cookie = true; 4413 tree arg_types; 4414 4415 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 4416 /* Skip the size_t parameter. */ 4417 arg_types = TREE_CHAIN (arg_types); 4418 /* Check the remaining parameters (if any). */ 4419 if (arg_types 4420 && TREE_CHAIN (arg_types) == void_list_node 4421 && same_type_p (TREE_VALUE (arg_types), 4422 ptr_type_node)) 4423 use_cookie = false; 4424 /* If we need a cookie, adjust the number of bytes allocated. */ 4425 if (use_cookie) 4426 { 4427 /* Update the total size. */ 4428 *size = size_binop (PLUS_EXPR, original_size, *cookie_size); 4429 if (size_check) 4430 { 4431 /* Set to (size_t)-1 if the size check fails. */ 4432 gcc_assert (size_check != NULL_TREE); 4433 *size = fold_build3 (COND_EXPR, sizetype, size_check, 4434 *size, TYPE_MAX_VALUE (sizetype)); 4435 } 4436 /* Update the argument list to reflect the adjusted size. */ 4437 (**args)[0] = *size; 4438 } 4439 else 4440 *cookie_size = NULL_TREE; 4441 } 4442 4443 /* Tell our caller which function we decided to call. */ 4444 if (fn) 4445 *fn = cand->fn; 4446 4447 /* Build the CALL_EXPR. */ 4448 return build_over_call (cand, LOOKUP_NORMAL, complain); 4449 } 4450 4451 /* Build a new call to operator(). This may change ARGS. */ 4452 4453 static tree 4454 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4455 { 4456 struct z_candidate *candidates = 0, *cand; 4457 tree fns, convs, first_mem_arg = NULL_TREE; 4458 bool any_viable_p; 4459 tree result = NULL_TREE; 4460 void *p; 4461 4462 obj = mark_lvalue_use (obj); 4463 4464 if (error_operand_p (obj)) 4465 return error_mark_node; 4466 4467 tree type = TREE_TYPE (obj); 4468 4469 obj = prep_operand (obj); 4470 4471 if (TYPE_PTRMEMFUNC_P (type)) 4472 { 4473 if (complain & tf_error) 4474 /* It's no good looking for an overloaded operator() on a 4475 pointer-to-member-function. */ 4476 error ("pointer-to-member function %qE cannot be called without " 4477 "an object; consider using %<.*%> or %<->*%>", obj); 4478 return error_mark_node; 4479 } 4480 4481 if (TYPE_BINFO (type)) 4482 { 4483 fns = lookup_fnfields (TYPE_BINFO (type), call_op_identifier, 1); 4484 if (fns == error_mark_node) 4485 return error_mark_node; 4486 } 4487 else 4488 fns = NULL_TREE; 4489 4490 if (args != NULL && *args != NULL) 4491 { 4492 *args = resolve_args (*args, complain); 4493 if (*args == NULL) 4494 return error_mark_node; 4495 } 4496 4497 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 4498 p = conversion_obstack_alloc (0); 4499 4500 if (fns) 4501 { 4502 first_mem_arg = obj; 4503 4504 add_candidates (BASELINK_FUNCTIONS (fns), 4505 first_mem_arg, *args, NULL_TREE, 4506 NULL_TREE, false, 4507 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns), 4508 LOOKUP_NORMAL, &candidates, complain); 4509 } 4510 4511 convs = lookup_conversions (type); 4512 4513 for (; convs; convs = TREE_CHAIN (convs)) 4514 { 4515 tree totype = TREE_TYPE (convs); 4516 4517 if (TYPE_PTRFN_P (totype) 4518 || TYPE_REFFN_P (totype) 4519 || (TREE_CODE (totype) == REFERENCE_TYPE 4520 && TYPE_PTRFN_P (TREE_TYPE (totype)))) 4521 for (ovl_iterator iter (TREE_VALUE (convs)); iter; ++iter) 4522 { 4523 tree fn = *iter; 4524 4525 if (DECL_NONCONVERTING_P (fn)) 4526 continue; 4527 4528 if (TREE_CODE (fn) == TEMPLATE_DECL) 4529 add_template_conv_candidate 4530 (&candidates, fn, obj, *args, totype, 4531 /*access_path=*/NULL_TREE, 4532 /*conversion_path=*/NULL_TREE, complain); 4533 else 4534 add_conv_candidate (&candidates, fn, obj, 4535 *args, /*conversion_path=*/NULL_TREE, 4536 /*access_path=*/NULL_TREE, complain); 4537 } 4538 } 4539 4540 /* Be strict here because if we choose a bad conversion candidate, the 4541 errors we get won't mention the call context. */ 4542 candidates = splice_viable (candidates, true, &any_viable_p); 4543 if (!any_viable_p) 4544 { 4545 if (complain & tf_error) 4546 { 4547 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), 4548 build_tree_list_vec (*args)); 4549 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4550 } 4551 result = error_mark_node; 4552 } 4553 else 4554 { 4555 cand = tourney (candidates, complain); 4556 if (cand == 0) 4557 { 4558 if (complain & tf_error) 4559 { 4560 error ("call of %<(%T) (%A)%> is ambiguous", 4561 TREE_TYPE (obj), build_tree_list_vec (*args)); 4562 print_z_candidates (location_of (TREE_TYPE (obj)), candidates); 4563 } 4564 result = error_mark_node; 4565 } 4566 else if (TREE_CODE (cand->fn) == FUNCTION_DECL 4567 && DECL_OVERLOADED_OPERATOR_P (cand->fn) 4568 && DECL_OVERLOADED_OPERATOR_IS (cand->fn, CALL_EXPR)) 4569 result = build_over_call (cand, LOOKUP_NORMAL, complain); 4570 else 4571 { 4572 if (TREE_CODE (cand->fn) == FUNCTION_DECL) 4573 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, 4574 -1, complain); 4575 else 4576 { 4577 gcc_checking_assert (TYPE_P (cand->fn)); 4578 obj = convert_like (cand->convs[0], obj, complain); 4579 } 4580 obj = convert_from_reference (obj); 4581 result = cp_build_function_call_vec (obj, args, complain); 4582 } 4583 } 4584 4585 /* Free all the conversions we allocated. */ 4586 obstack_free (&conversion_obstack, p); 4587 4588 return result; 4589 } 4590 4591 /* Wrapper for above. */ 4592 4593 tree 4594 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain) 4595 { 4596 tree ret; 4597 bool subtime = timevar_cond_start (TV_OVERLOAD); 4598 ret = build_op_call_1 (obj, args, complain); 4599 timevar_cond_stop (TV_OVERLOAD, subtime); 4600 return ret; 4601 } 4602 4603 /* Called by op_error to prepare format strings suitable for the error 4604 function. It concatenates a prefix (controlled by MATCH), ERRMSG, 4605 and a suffix (controlled by NTYPES). */ 4606 4607 static const char * 4608 op_error_string (const char *errmsg, int ntypes, bool match) 4609 { 4610 const char *msg; 4611 4612 const char *msgp = concat (match ? G_("ambiguous overload for ") 4613 : G_("no match for "), errmsg, NULL); 4614 4615 if (ntypes == 3) 4616 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL); 4617 else if (ntypes == 2) 4618 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL); 4619 else 4620 msg = concat (msgp, G_(" (operand type is %qT)"), NULL); 4621 4622 return msg; 4623 } 4624 4625 static void 4626 op_error (location_t loc, enum tree_code code, enum tree_code code2, 4627 tree arg1, tree arg2, tree arg3, bool match) 4628 { 4629 bool assop = code == MODIFY_EXPR; 4630 const char *opname = OVL_OP_INFO (assop, assop ? code2 : code)->name; 4631 4632 switch (code) 4633 { 4634 case COND_EXPR: 4635 if (flag_diagnostics_show_caret) 4636 error_at (loc, op_error_string (G_("ternary %<operator?:%>"), 4637 3, match), 4638 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4639 else 4640 error_at (loc, op_error_string (G_("ternary %<operator?:%> " 4641 "in %<%E ? %E : %E%>"), 3, match), 4642 arg1, arg2, arg3, 4643 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3)); 4644 break; 4645 4646 case POSTINCREMENT_EXPR: 4647 case POSTDECREMENT_EXPR: 4648 if (flag_diagnostics_show_caret) 4649 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4650 opname, TREE_TYPE (arg1)); 4651 else 4652 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"), 4653 1, match), 4654 opname, arg1, opname, TREE_TYPE (arg1)); 4655 break; 4656 4657 case ARRAY_REF: 4658 if (flag_diagnostics_show_caret) 4659 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match), 4660 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4661 else 4662 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"), 4663 2, match), 4664 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4665 break; 4666 4667 case REALPART_EXPR: 4668 case IMAGPART_EXPR: 4669 if (flag_diagnostics_show_caret) 4670 error_at (loc, op_error_string (G_("%qs"), 1, match), 4671 opname, TREE_TYPE (arg1)); 4672 else 4673 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match), 4674 opname, opname, arg1, TREE_TYPE (arg1)); 4675 break; 4676 4677 default: 4678 if (arg2) 4679 if (flag_diagnostics_show_caret) 4680 error_at (loc, op_error_string (G_("%<operator%s%>"), 2, match), 4681 opname, TREE_TYPE (arg1), TREE_TYPE (arg2)); 4682 else 4683 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"), 4684 2, match), 4685 opname, arg1, opname, arg2, 4686 TREE_TYPE (arg1), TREE_TYPE (arg2)); 4687 else 4688 if (flag_diagnostics_show_caret) 4689 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match), 4690 opname, TREE_TYPE (arg1)); 4691 else 4692 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"), 4693 1, match), 4694 opname, opname, arg1, TREE_TYPE (arg1)); 4695 break; 4696 } 4697 } 4698 4699 /* Return the implicit conversion sequence that could be used to 4700 convert E1 to E2 in [expr.cond]. */ 4701 4702 static conversion * 4703 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain) 4704 { 4705 tree t1 = non_reference (TREE_TYPE (e1)); 4706 tree t2 = non_reference (TREE_TYPE (e2)); 4707 conversion *conv; 4708 bool good_base; 4709 4710 /* [expr.cond] 4711 4712 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 4713 implicitly converted (clause _conv_) to the type "lvalue reference to 4714 T2", subject to the constraint that in the conversion the 4715 reference must bind directly (_dcl.init.ref_) to an lvalue. 4716 4717 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be 4718 implicitly converted to the type "rvalue reference to T2", subject to 4719 the constraint that the reference must bind directly. */ 4720 if (glvalue_p (e2)) 4721 { 4722 tree rtype = cp_build_reference_type (t2, !lvalue_p (e2)); 4723 conv = implicit_conversion (rtype, 4724 t1, 4725 e1, 4726 /*c_cast_p=*/false, 4727 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND 4728 |LOOKUP_ONLYCONVERTING, 4729 complain); 4730 if (conv && !conv->bad_p) 4731 return conv; 4732 } 4733 4734 /* If E2 is a prvalue or if neither of the conversions above can be done 4735 and at least one of the operands has (possibly cv-qualified) class 4736 type: */ 4737 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2)) 4738 return NULL; 4739 4740 /* [expr.cond] 4741 4742 If E1 and E2 have class type, and the underlying class types are 4743 the same or one is a base class of the other: E1 can be converted 4744 to match E2 if the class of T2 is the same type as, or a base 4745 class of, the class of T1, and the cv-qualification of T2 is the 4746 same cv-qualification as, or a greater cv-qualification than, the 4747 cv-qualification of T1. If the conversion is applied, E1 is 4748 changed to an rvalue of type T2 that still refers to the original 4749 source class object (or the appropriate subobject thereof). */ 4750 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2) 4751 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2))) 4752 { 4753 if (good_base && at_least_as_qualified_p (t2, t1)) 4754 { 4755 conv = build_identity_conv (t1, e1); 4756 if (!same_type_p (TYPE_MAIN_VARIANT (t1), 4757 TYPE_MAIN_VARIANT (t2))) 4758 conv = build_conv (ck_base, t2, conv); 4759 else 4760 conv = build_conv (ck_rvalue, t2, conv); 4761 return conv; 4762 } 4763 else 4764 return NULL; 4765 } 4766 else 4767 /* [expr.cond] 4768 4769 Otherwise: E1 can be converted to match E2 if E1 can be implicitly 4770 converted to the type that expression E2 would have if E2 were 4771 converted to an rvalue (or the type it has, if E2 is an rvalue). */ 4772 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false, 4773 LOOKUP_IMPLICIT, complain); 4774 } 4775 4776 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three 4777 arguments to the conditional expression. */ 4778 4779 static tree 4780 build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3, 4781 tsubst_flags_t complain) 4782 { 4783 tree arg2_type; 4784 tree arg3_type; 4785 tree result = NULL_TREE; 4786 tree result_type = NULL_TREE; 4787 bool is_glvalue = true; 4788 struct z_candidate *candidates = 0; 4789 struct z_candidate *cand; 4790 void *p; 4791 tree orig_arg2, orig_arg3; 4792 4793 /* As a G++ extension, the second argument to the conditional can be 4794 omitted. (So that `a ? : c' is roughly equivalent to `a ? a : 4795 c'.) If the second operand is omitted, make sure it is 4796 calculated only once. */ 4797 if (!arg2) 4798 { 4799 if (complain & tf_error) 4800 pedwarn (loc, OPT_Wpedantic, 4801 "ISO C++ forbids omitting the middle term of a ?: expression"); 4802 4803 if ((complain & tf_warning) && !truth_value_p (TREE_CODE (arg1))) 4804 warn_for_omitted_condop (loc, arg1); 4805 4806 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */ 4807 if (lvalue_p (arg1)) 4808 arg2 = arg1 = cp_stabilize_reference (arg1); 4809 else 4810 arg2 = arg1 = cp_save_expr (arg1); 4811 } 4812 4813 /* If something has already gone wrong, just pass that fact up the 4814 tree. */ 4815 if (error_operand_p (arg1) 4816 || error_operand_p (arg2) 4817 || error_operand_p (arg3)) 4818 return error_mark_node; 4819 4820 orig_arg2 = arg2; 4821 orig_arg3 = arg3; 4822 4823 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1))) 4824 { 4825 tree arg1_type = TREE_TYPE (arg1); 4826 4827 /* If arg1 is another cond_expr choosing between -1 and 0, 4828 then we can use its comparison. It may help to avoid 4829 additional comparison, produce more accurate diagnostics 4830 and enables folding. */ 4831 if (TREE_CODE (arg1) == VEC_COND_EXPR 4832 && integer_minus_onep (TREE_OPERAND (arg1, 1)) 4833 && integer_zerop (TREE_OPERAND (arg1, 2))) 4834 arg1 = TREE_OPERAND (arg1, 0); 4835 4836 arg1 = force_rvalue (arg1, complain); 4837 arg2 = force_rvalue (arg2, complain); 4838 arg3 = force_rvalue (arg3, complain); 4839 4840 /* force_rvalue can return error_mark on valid arguments. */ 4841 if (error_operand_p (arg1) 4842 || error_operand_p (arg2) 4843 || error_operand_p (arg3)) 4844 return error_mark_node; 4845 4846 arg2_type = TREE_TYPE (arg2); 4847 arg3_type = TREE_TYPE (arg3); 4848 4849 if (!VECTOR_TYPE_P (arg2_type) 4850 && !VECTOR_TYPE_P (arg3_type)) 4851 { 4852 /* Rely on the error messages of the scalar version. */ 4853 tree scal = build_conditional_expr_1 (loc, integer_one_node, 4854 orig_arg2, orig_arg3, complain); 4855 if (scal == error_mark_node) 4856 return error_mark_node; 4857 tree stype = TREE_TYPE (scal); 4858 tree ctype = TREE_TYPE (arg1_type); 4859 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype) 4860 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype))) 4861 { 4862 if (complain & tf_error) 4863 error_at (loc, "inferred scalar type %qT is not an integer or " 4864 "floating point type of the same size as %qT", stype, 4865 COMPARISON_CLASS_P (arg1) 4866 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0))) 4867 : ctype); 4868 return error_mark_node; 4869 } 4870 4871 tree vtype = build_opaque_vector_type (stype, 4872 TYPE_VECTOR_SUBPARTS (arg1_type)); 4873 /* We could pass complain & tf_warning to unsafe_conversion_p, 4874 but the warnings (like Wsign-conversion) have already been 4875 given by the scalar build_conditional_expr_1. We still check 4876 unsafe_conversion_p to forbid truncating long long -> float. */ 4877 if (unsafe_conversion_p (loc, stype, arg2, NULL_TREE, false)) 4878 { 4879 if (complain & tf_error) 4880 error_at (loc, "conversion of scalar %qH to vector %qI " 4881 "involves truncation", arg2_type, vtype); 4882 return error_mark_node; 4883 } 4884 if (unsafe_conversion_p (loc, stype, arg3, NULL_TREE, false)) 4885 { 4886 if (complain & tf_error) 4887 error_at (loc, "conversion of scalar %qH to vector %qI " 4888 "involves truncation", arg3_type, vtype); 4889 return error_mark_node; 4890 } 4891 4892 arg2 = cp_convert (stype, arg2, complain); 4893 arg2 = save_expr (arg2); 4894 arg2 = build_vector_from_val (vtype, arg2); 4895 arg2_type = vtype; 4896 arg3 = cp_convert (stype, arg3, complain); 4897 arg3 = save_expr (arg3); 4898 arg3 = build_vector_from_val (vtype, arg3); 4899 arg3_type = vtype; 4900 } 4901 4902 if (VECTOR_TYPE_P (arg2_type) != VECTOR_TYPE_P (arg3_type)) 4903 { 4904 enum stv_conv convert_flag = 4905 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3, 4906 complain & tf_error); 4907 4908 switch (convert_flag) 4909 { 4910 case stv_error: 4911 return error_mark_node; 4912 case stv_firstarg: 4913 { 4914 arg2 = save_expr (arg2); 4915 arg2 = convert (TREE_TYPE (arg3_type), arg2); 4916 arg2 = build_vector_from_val (arg3_type, arg2); 4917 arg2_type = TREE_TYPE (arg2); 4918 break; 4919 } 4920 case stv_secondarg: 4921 { 4922 arg3 = save_expr (arg3); 4923 arg3 = convert (TREE_TYPE (arg2_type), arg3); 4924 arg3 = build_vector_from_val (arg2_type, arg3); 4925 arg3_type = TREE_TYPE (arg3); 4926 break; 4927 } 4928 default: 4929 break; 4930 } 4931 } 4932 4933 if (!same_type_p (arg2_type, arg3_type) 4934 || maybe_ne (TYPE_VECTOR_SUBPARTS (arg1_type), 4935 TYPE_VECTOR_SUBPARTS (arg2_type)) 4936 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type)) 4937 { 4938 if (complain & tf_error) 4939 error_at (loc, 4940 "incompatible vector types in conditional expression: " 4941 "%qT, %qT and %qT", TREE_TYPE (arg1), 4942 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3)); 4943 return error_mark_node; 4944 } 4945 4946 if (!COMPARISON_CLASS_P (arg1)) 4947 { 4948 tree cmp_type = build_same_sized_truth_vector_type (arg1_type); 4949 arg1 = build2 (NE_EXPR, cmp_type, arg1, build_zero_cst (arg1_type)); 4950 } 4951 return build3_loc (loc, VEC_COND_EXPR, arg2_type, arg1, arg2, arg3); 4952 } 4953 4954 /* [expr.cond] 4955 4956 The first expression is implicitly converted to bool (clause 4957 _conv_). */ 4958 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain, 4959 LOOKUP_NORMAL); 4960 if (error_operand_p (arg1)) 4961 return error_mark_node; 4962 4963 /* [expr.cond] 4964 4965 If either the second or the third operand has type (possibly 4966 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_), 4967 array-to-pointer (_conv.array_), and function-to-pointer 4968 (_conv.func_) standard conversions are performed on the second 4969 and third operands. */ 4970 arg2_type = unlowered_expr_type (arg2); 4971 arg3_type = unlowered_expr_type (arg3); 4972 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type)) 4973 { 4974 /* Do the conversions. We don't these for `void' type arguments 4975 since it can't have any effect and since decay_conversion 4976 does not handle that case gracefully. */ 4977 if (!VOID_TYPE_P (arg2_type)) 4978 arg2 = decay_conversion (arg2, complain); 4979 if (!VOID_TYPE_P (arg3_type)) 4980 arg3 = decay_conversion (arg3, complain); 4981 arg2_type = TREE_TYPE (arg2); 4982 arg3_type = TREE_TYPE (arg3); 4983 4984 /* [expr.cond] 4985 4986 One of the following shall hold: 4987 4988 --The second or the third operand (but not both) is a 4989 throw-expression (_except.throw_); the result is of the 4990 type of the other and is an rvalue. 4991 4992 --Both the second and the third operands have type void; the 4993 result is of type void and is an rvalue. 4994 4995 We must avoid calling force_rvalue for expressions of type 4996 "void" because it will complain that their value is being 4997 used. */ 4998 if (TREE_CODE (arg2) == THROW_EXPR 4999 && TREE_CODE (arg3) != THROW_EXPR) 5000 { 5001 if (!VOID_TYPE_P (arg3_type)) 5002 { 5003 arg3 = force_rvalue (arg3, complain); 5004 if (arg3 == error_mark_node) 5005 return error_mark_node; 5006 } 5007 arg3_type = TREE_TYPE (arg3); 5008 result_type = arg3_type; 5009 } 5010 else if (TREE_CODE (arg2) != THROW_EXPR 5011 && TREE_CODE (arg3) == THROW_EXPR) 5012 { 5013 if (!VOID_TYPE_P (arg2_type)) 5014 { 5015 arg2 = force_rvalue (arg2, complain); 5016 if (arg2 == error_mark_node) 5017 return error_mark_node; 5018 } 5019 arg2_type = TREE_TYPE (arg2); 5020 result_type = arg2_type; 5021 } 5022 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type)) 5023 result_type = void_type_node; 5024 else 5025 { 5026 if (complain & tf_error) 5027 { 5028 if (VOID_TYPE_P (arg2_type)) 5029 error_at (EXPR_LOC_OR_LOC (arg3, loc), 5030 "second operand to the conditional operator " 5031 "is of type %<void%>, but the third operand is " 5032 "neither a throw-expression nor of type %<void%>"); 5033 else 5034 error_at (EXPR_LOC_OR_LOC (arg2, loc), 5035 "third operand to the conditional operator " 5036 "is of type %<void%>, but the second operand is " 5037 "neither a throw-expression nor of type %<void%>"); 5038 } 5039 return error_mark_node; 5040 } 5041 5042 is_glvalue = false; 5043 goto valid_operands; 5044 } 5045 /* [expr.cond] 5046 5047 Otherwise, if the second and third operand have different types, 5048 and either has (possibly cv-qualified) class type, or if both are 5049 glvalues of the same value category and the same type except for 5050 cv-qualification, an attempt is made to convert each of those operands 5051 to the type of the other. */ 5052 else if (!same_type_p (arg2_type, arg3_type) 5053 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type) 5054 || (same_type_ignoring_top_level_qualifiers_p (arg2_type, 5055 arg3_type) 5056 && glvalue_p (arg2) && glvalue_p (arg3) 5057 && lvalue_p (arg2) == lvalue_p (arg3)))) 5058 { 5059 conversion *conv2; 5060 conversion *conv3; 5061 bool converted = false; 5062 5063 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5064 p = conversion_obstack_alloc (0); 5065 5066 conv2 = conditional_conversion (arg2, arg3, complain); 5067 conv3 = conditional_conversion (arg3, arg2, complain); 5068 5069 /* [expr.cond] 5070 5071 If both can be converted, or one can be converted but the 5072 conversion is ambiguous, the program is ill-formed. If 5073 neither can be converted, the operands are left unchanged and 5074 further checking is performed as described below. If exactly 5075 one conversion is possible, that conversion is applied to the 5076 chosen operand and the converted operand is used in place of 5077 the original operand for the remainder of this section. */ 5078 if ((conv2 && !conv2->bad_p 5079 && conv3 && !conv3->bad_p) 5080 || (conv2 && conv2->kind == ck_ambig) 5081 || (conv3 && conv3->kind == ck_ambig)) 5082 { 5083 if (complain & tf_error) 5084 { 5085 error_at (loc, "operands to ?: have different types %qT and %qT", 5086 arg2_type, arg3_type); 5087 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p) 5088 inform (loc, " and each type can be converted to the other"); 5089 else if (conv2 && conv2->kind == ck_ambig) 5090 convert_like (conv2, arg2, complain); 5091 else 5092 convert_like (conv3, arg3, complain); 5093 } 5094 result = error_mark_node; 5095 } 5096 else if (conv2 && !conv2->bad_p) 5097 { 5098 arg2 = convert_like (conv2, arg2, complain); 5099 arg2 = convert_from_reference (arg2); 5100 arg2_type = TREE_TYPE (arg2); 5101 /* Even if CONV2 is a valid conversion, the result of the 5102 conversion may be invalid. For example, if ARG3 has type 5103 "volatile X", and X does not have a copy constructor 5104 accepting a "volatile X&", then even if ARG2 can be 5105 converted to X, the conversion will fail. */ 5106 if (error_operand_p (arg2)) 5107 result = error_mark_node; 5108 converted = true; 5109 } 5110 else if (conv3 && !conv3->bad_p) 5111 { 5112 arg3 = convert_like (conv3, arg3, complain); 5113 arg3 = convert_from_reference (arg3); 5114 arg3_type = TREE_TYPE (arg3); 5115 if (error_operand_p (arg3)) 5116 result = error_mark_node; 5117 converted = true; 5118 } 5119 5120 /* Free all the conversions we allocated. */ 5121 obstack_free (&conversion_obstack, p); 5122 5123 if (result) 5124 return result; 5125 5126 /* If, after the conversion, both operands have class type, 5127 treat the cv-qualification of both operands as if it were the 5128 union of the cv-qualification of the operands. 5129 5130 The standard is not clear about what to do in this 5131 circumstance. For example, if the first operand has type 5132 "const X" and the second operand has a user-defined 5133 conversion to "volatile X", what is the type of the second 5134 operand after this step? Making it be "const X" (matching 5135 the first operand) seems wrong, as that discards the 5136 qualification without actually performing a copy. Leaving it 5137 as "volatile X" seems wrong as that will result in the 5138 conditional expression failing altogether, even though, 5139 according to this step, the one operand could be converted to 5140 the type of the other. */ 5141 if (converted 5142 && CLASS_TYPE_P (arg2_type) 5143 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type)) 5144 arg2_type = arg3_type = 5145 cp_build_qualified_type (arg2_type, 5146 cp_type_quals (arg2_type) 5147 | cp_type_quals (arg3_type)); 5148 } 5149 5150 /* [expr.cond] 5151 5152 If the second and third operands are glvalues of the same value 5153 category and have the same type, the result is of that type and 5154 value category. */ 5155 if (((lvalue_p (arg2) && lvalue_p (arg3)) 5156 || (xvalue_p (arg2) && xvalue_p (arg3))) 5157 && same_type_p (arg2_type, arg3_type)) 5158 { 5159 result_type = arg2_type; 5160 if (processing_template_decl) 5161 /* Let lvalue_kind know this was a glvalue. */ 5162 result_type = cp_build_reference_type (result_type, xvalue_p (arg2)); 5163 5164 arg2 = mark_lvalue_use (arg2); 5165 arg3 = mark_lvalue_use (arg3); 5166 goto valid_operands; 5167 } 5168 5169 /* [expr.cond] 5170 5171 Otherwise, the result is an rvalue. If the second and third 5172 operand do not have the same type, and either has (possibly 5173 cv-qualified) class type, overload resolution is used to 5174 determine the conversions (if any) to be applied to the operands 5175 (_over.match.oper_, _over.built_). */ 5176 is_glvalue = false; 5177 if (!same_type_p (arg2_type, arg3_type) 5178 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type))) 5179 { 5180 tree args[3]; 5181 conversion *conv; 5182 bool any_viable_p; 5183 5184 /* Rearrange the arguments so that add_builtin_candidate only has 5185 to know about two args. In build_builtin_candidate, the 5186 arguments are unscrambled. */ 5187 args[0] = arg2; 5188 args[1] = arg3; 5189 args[2] = arg1; 5190 add_builtin_candidates (&candidates, 5191 COND_EXPR, 5192 NOP_EXPR, 5193 ovl_op_identifier (false, COND_EXPR), 5194 args, 5195 LOOKUP_NORMAL, complain); 5196 5197 /* [expr.cond] 5198 5199 If the overload resolution fails, the program is 5200 ill-formed. */ 5201 candidates = splice_viable (candidates, false, &any_viable_p); 5202 if (!any_viable_p) 5203 { 5204 if (complain & tf_error) 5205 error_at (loc, "operands to ?: have different types %qT and %qT", 5206 arg2_type, arg3_type); 5207 return error_mark_node; 5208 } 5209 cand = tourney (candidates, complain); 5210 if (!cand) 5211 { 5212 if (complain & tf_error) 5213 { 5214 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE); 5215 print_z_candidates (loc, candidates); 5216 } 5217 return error_mark_node; 5218 } 5219 5220 /* [expr.cond] 5221 5222 Otherwise, the conversions thus determined are applied, and 5223 the converted operands are used in place of the original 5224 operands for the remainder of this section. */ 5225 conv = cand->convs[0]; 5226 arg1 = convert_like (conv, arg1, complain); 5227 conv = cand->convs[1]; 5228 arg2 = convert_like (conv, arg2, complain); 5229 arg2_type = TREE_TYPE (arg2); 5230 conv = cand->convs[2]; 5231 arg3 = convert_like (conv, arg3, complain); 5232 arg3_type = TREE_TYPE (arg3); 5233 } 5234 5235 /* [expr.cond] 5236 5237 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_), 5238 and function-to-pointer (_conv.func_) standard conversions are 5239 performed on the second and third operands. 5240 5241 We need to force the lvalue-to-rvalue conversion here for class types, 5242 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues 5243 that isn't wrapped with a TARGET_EXPR plays havoc with exception 5244 regions. */ 5245 5246 arg2 = force_rvalue (arg2, complain); 5247 if (!CLASS_TYPE_P (arg2_type)) 5248 arg2_type = TREE_TYPE (arg2); 5249 5250 arg3 = force_rvalue (arg3, complain); 5251 if (!CLASS_TYPE_P (arg3_type)) 5252 arg3_type = TREE_TYPE (arg3); 5253 5254 if (arg2 == error_mark_node || arg3 == error_mark_node) 5255 return error_mark_node; 5256 5257 /* [expr.cond] 5258 5259 After those conversions, one of the following shall hold: 5260 5261 --The second and third operands have the same type; the result is of 5262 that type. */ 5263 if (same_type_p (arg2_type, arg3_type)) 5264 result_type = arg2_type; 5265 /* [expr.cond] 5266 5267 --The second and third operands have arithmetic or enumeration 5268 type; the usual arithmetic conversions are performed to bring 5269 them to a common type, and the result is of that type. */ 5270 else if ((ARITHMETIC_TYPE_P (arg2_type) 5271 || UNSCOPED_ENUM_P (arg2_type)) 5272 && (ARITHMETIC_TYPE_P (arg3_type) 5273 || UNSCOPED_ENUM_P (arg3_type))) 5274 { 5275 /* In this case, there is always a common type. */ 5276 result_type = type_after_usual_arithmetic_conversions (arg2_type, 5277 arg3_type); 5278 if (complain & tf_warning) 5279 do_warn_double_promotion (result_type, arg2_type, arg3_type, 5280 "implicit conversion from %qH to %qI to " 5281 "match other result of conditional", 5282 loc); 5283 5284 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE 5285 && TREE_CODE (arg3_type) == ENUMERAL_TYPE) 5286 { 5287 if (TREE_CODE (orig_arg2) == CONST_DECL 5288 && TREE_CODE (orig_arg3) == CONST_DECL 5289 && DECL_CONTEXT (orig_arg2) == DECL_CONTEXT (orig_arg3)) 5290 /* Two enumerators from the same enumeration can have different 5291 types when the enumeration is still being defined. */; 5292 else if (complain & tf_warning) 5293 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in " 5294 "conditional expression: %qT vs %qT", 5295 arg2_type, arg3_type); 5296 } 5297 else if (extra_warnings 5298 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE 5299 && !same_type_p (arg3_type, type_promotes_to (arg2_type))) 5300 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE 5301 && !same_type_p (arg2_type, 5302 type_promotes_to (arg3_type))))) 5303 { 5304 if (complain & tf_warning) 5305 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in " 5306 "conditional expression"); 5307 } 5308 5309 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5310 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5311 } 5312 /* [expr.cond] 5313 5314 --The second and third operands have pointer type, or one has 5315 pointer type and the other is a null pointer constant; pointer 5316 conversions (_conv.ptr_) and qualification conversions 5317 (_conv.qual_) are performed to bring them to their composite 5318 pointer type (_expr.rel_). The result is of the composite 5319 pointer type. 5320 5321 --The second and third operands have pointer to member type, or 5322 one has pointer to member type and the other is a null pointer 5323 constant; pointer to member conversions (_conv.mem_) and 5324 qualification conversions (_conv.qual_) are performed to bring 5325 them to a common type, whose cv-qualification shall match the 5326 cv-qualification of either the second or the third operand. 5327 The result is of the common type. */ 5328 else if ((null_ptr_cst_p (arg2) 5329 && TYPE_PTR_OR_PTRMEM_P (arg3_type)) 5330 || (null_ptr_cst_p (arg3) 5331 && TYPE_PTR_OR_PTRMEM_P (arg2_type)) 5332 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type)) 5333 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type)) 5334 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type))) 5335 { 5336 result_type = composite_pointer_type (arg2_type, arg3_type, arg2, 5337 arg3, CPO_CONDITIONAL_EXPR, 5338 complain); 5339 if (result_type == error_mark_node) 5340 return error_mark_node; 5341 arg2 = perform_implicit_conversion (result_type, arg2, complain); 5342 arg3 = perform_implicit_conversion (result_type, arg3, complain); 5343 } 5344 5345 if (!result_type) 5346 { 5347 if (complain & tf_error) 5348 error_at (loc, "operands to ?: have different types %qT and %qT", 5349 arg2_type, arg3_type); 5350 return error_mark_node; 5351 } 5352 5353 if (arg2 == error_mark_node || arg3 == error_mark_node) 5354 return error_mark_node; 5355 5356 valid_operands: 5357 result = build3_loc (loc, COND_EXPR, result_type, arg1, arg2, arg3); 5358 5359 /* If the ARG2 and ARG3 are the same and don't have side-effects, 5360 warn here, because the COND_EXPR will be turned into ARG2. */ 5361 if (warn_duplicated_branches 5362 && (complain & tf_warning) 5363 && (arg2 == arg3 || operand_equal_p (arg2, arg3, 0))) 5364 warning_at (EXPR_LOCATION (result), OPT_Wduplicated_branches, 5365 "this condition has identical branches"); 5366 5367 /* We can't use result_type below, as fold might have returned a 5368 throw_expr. */ 5369 5370 if (!is_glvalue) 5371 { 5372 /* Expand both sides into the same slot, hopefully the target of 5373 the ?: expression. We used to check for TARGET_EXPRs here, 5374 but now we sometimes wrap them in NOP_EXPRs so the test would 5375 fail. */ 5376 if (CLASS_TYPE_P (TREE_TYPE (result))) 5377 result = get_target_expr_sfinae (result, complain); 5378 /* If this expression is an rvalue, but might be mistaken for an 5379 lvalue, we must add a NON_LVALUE_EXPR. */ 5380 result = rvalue (result); 5381 } 5382 else 5383 result = force_paren_expr (result); 5384 5385 return result; 5386 } 5387 5388 /* Wrapper for above. */ 5389 5390 tree 5391 build_conditional_expr (location_t loc, tree arg1, tree arg2, tree arg3, 5392 tsubst_flags_t complain) 5393 { 5394 tree ret; 5395 bool subtime = timevar_cond_start (TV_OVERLOAD); 5396 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain); 5397 timevar_cond_stop (TV_OVERLOAD, subtime); 5398 return ret; 5399 } 5400 5401 /* OPERAND is an operand to an expression. Perform necessary steps 5402 required before using it. If OPERAND is NULL_TREE, NULL_TREE is 5403 returned. */ 5404 5405 static tree 5406 prep_operand (tree operand) 5407 { 5408 if (operand) 5409 { 5410 if (CLASS_TYPE_P (TREE_TYPE (operand)) 5411 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand))) 5412 /* Make sure the template type is instantiated now. */ 5413 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand))); 5414 } 5415 5416 return operand; 5417 } 5418 5419 /* Add each of the viable functions in FNS (a FUNCTION_DECL or 5420 OVERLOAD) to the CANDIDATES, returning an updated list of 5421 CANDIDATES. The ARGS are the arguments provided to the call; 5422 if FIRST_ARG is non-null it is the implicit object argument, 5423 otherwise the first element of ARGS is used if needed. The 5424 EXPLICIT_TARGS are explicit template arguments provided. 5425 TEMPLATE_ONLY is true if only template functions should be 5426 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for 5427 add_function_candidate. */ 5428 5429 static void 5430 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args, 5431 tree return_type, 5432 tree explicit_targs, bool template_only, 5433 tree conversion_path, tree access_path, 5434 int flags, 5435 struct z_candidate **candidates, 5436 tsubst_flags_t complain) 5437 { 5438 tree ctype; 5439 const vec<tree, va_gc> *non_static_args; 5440 bool check_list_ctor = false; 5441 bool check_converting = false; 5442 unification_kind_t strict; 5443 5444 if (!fns) 5445 return; 5446 5447 /* Precalculate special handling of constructors and conversion ops. */ 5448 tree fn = OVL_FIRST (fns); 5449 if (DECL_CONV_FN_P (fn)) 5450 { 5451 check_list_ctor = false; 5452 check_converting = (flags & LOOKUP_ONLYCONVERTING) != 0; 5453 if (flags & LOOKUP_NO_CONVERSION) 5454 /* We're doing return_type(x). */ 5455 strict = DEDUCE_CONV; 5456 else 5457 /* We're doing x.operator return_type(). */ 5458 strict = DEDUCE_EXACT; 5459 /* [over.match.funcs] For conversion functions, the function 5460 is considered to be a member of the class of the implicit 5461 object argument for the purpose of defining the type of 5462 the implicit object parameter. */ 5463 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg)); 5464 } 5465 else 5466 { 5467 if (DECL_CONSTRUCTOR_P (fn)) 5468 { 5469 check_list_ctor = (flags & LOOKUP_LIST_ONLY) != 0; 5470 /* For list-initialization we consider explicit constructors 5471 and complain if one is chosen. */ 5472 check_converting 5473 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR)) 5474 == LOOKUP_ONLYCONVERTING); 5475 } 5476 strict = DEDUCE_CALL; 5477 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE; 5478 } 5479 5480 if (first_arg) 5481 non_static_args = args; 5482 else 5483 /* Delay creating the implicit this parameter until it is needed. */ 5484 non_static_args = NULL; 5485 5486 for (lkp_iterator iter (fns); iter; ++iter) 5487 { 5488 fn = *iter; 5489 5490 if (check_converting && DECL_NONCONVERTING_P (fn)) 5491 continue; 5492 if (check_list_ctor && !is_list_ctor (fn)) 5493 continue; 5494 5495 tree fn_first_arg = NULL_TREE; 5496 const vec<tree, va_gc> *fn_args = args; 5497 5498 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)) 5499 { 5500 /* Figure out where the object arg comes from. If this 5501 function is a non-static member and we didn't get an 5502 implicit object argument, move it out of args. */ 5503 if (first_arg == NULL_TREE) 5504 { 5505 unsigned int ix; 5506 tree arg; 5507 vec<tree, va_gc> *tempvec; 5508 vec_alloc (tempvec, args->length () - 1); 5509 for (ix = 1; args->iterate (ix, &arg); ++ix) 5510 tempvec->quick_push (arg); 5511 non_static_args = tempvec; 5512 first_arg = (*args)[0]; 5513 } 5514 5515 fn_first_arg = first_arg; 5516 fn_args = non_static_args; 5517 } 5518 5519 if (TREE_CODE (fn) == TEMPLATE_DECL) 5520 add_template_candidate (candidates, 5521 fn, 5522 ctype, 5523 explicit_targs, 5524 fn_first_arg, 5525 fn_args, 5526 return_type, 5527 access_path, 5528 conversion_path, 5529 flags, 5530 strict, 5531 complain); 5532 else if (!template_only) 5533 add_function_candidate (candidates, 5534 fn, 5535 ctype, 5536 fn_first_arg, 5537 fn_args, 5538 access_path, 5539 conversion_path, 5540 flags, 5541 complain); 5542 } 5543 } 5544 5545 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first, 5546 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */ 5547 5548 static int 5549 op_is_ordered (tree_code code) 5550 { 5551 switch (code) 5552 { 5553 // 5. b @= a 5554 case MODIFY_EXPR: 5555 return (flag_strong_eval_order > 1 ? -1 : 0); 5556 5557 // 6. a[b] 5558 case ARRAY_REF: 5559 return (flag_strong_eval_order > 1 ? 1 : 0); 5560 5561 // 1. a.b 5562 // Not overloadable (yet). 5563 // 2. a->b 5564 // Only one argument. 5565 // 3. a->*b 5566 case MEMBER_REF: 5567 // 7. a << b 5568 case LSHIFT_EXPR: 5569 // 8. a >> b 5570 case RSHIFT_EXPR: 5571 return (flag_strong_eval_order ? 1 : 0); 5572 5573 default: 5574 return 0; 5575 } 5576 } 5577 5578 static tree 5579 build_new_op_1 (location_t loc, enum tree_code code, int flags, tree arg1, 5580 tree arg2, tree arg3, tree *overload, tsubst_flags_t complain) 5581 { 5582 struct z_candidate *candidates = 0, *cand; 5583 vec<tree, va_gc> *arglist; 5584 tree args[3]; 5585 tree result = NULL_TREE; 5586 bool result_valid_p = false; 5587 enum tree_code code2 = NOP_EXPR; 5588 enum tree_code code_orig_arg1 = ERROR_MARK; 5589 enum tree_code code_orig_arg2 = ERROR_MARK; 5590 conversion *conv; 5591 void *p; 5592 bool strict_p; 5593 bool any_viable_p; 5594 5595 if (error_operand_p (arg1) 5596 || error_operand_p (arg2) 5597 || error_operand_p (arg3)) 5598 return error_mark_node; 5599 5600 bool ismodop = code == MODIFY_EXPR; 5601 if (ismodop) 5602 { 5603 code2 = TREE_CODE (arg3); 5604 arg3 = NULL_TREE; 5605 } 5606 tree fnname = ovl_op_identifier (ismodop, ismodop ? code2 : code); 5607 5608 arg1 = prep_operand (arg1); 5609 5610 bool memonly = false; 5611 switch (code) 5612 { 5613 case NEW_EXPR: 5614 case VEC_NEW_EXPR: 5615 case VEC_DELETE_EXPR: 5616 case DELETE_EXPR: 5617 /* Use build_op_new_call and build_op_delete_call instead. */ 5618 gcc_unreachable (); 5619 5620 case CALL_EXPR: 5621 /* Use build_op_call instead. */ 5622 gcc_unreachable (); 5623 5624 case TRUTH_ORIF_EXPR: 5625 case TRUTH_ANDIF_EXPR: 5626 case TRUTH_AND_EXPR: 5627 case TRUTH_OR_EXPR: 5628 /* These are saved for the sake of warn_logical_operator. */ 5629 code_orig_arg1 = TREE_CODE (arg1); 5630 code_orig_arg2 = TREE_CODE (arg2); 5631 break; 5632 case GT_EXPR: 5633 case LT_EXPR: 5634 case GE_EXPR: 5635 case LE_EXPR: 5636 case EQ_EXPR: 5637 case NE_EXPR: 5638 /* These are saved for the sake of maybe_warn_bool_compare. */ 5639 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1)); 5640 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2)); 5641 break; 5642 5643 /* =, ->, [], () must be non-static member functions. */ 5644 case MODIFY_EXPR: 5645 if (code2 != NOP_EXPR) 5646 break; 5647 /* FALLTHRU */ 5648 case COMPONENT_REF: 5649 case ARRAY_REF: 5650 memonly = true; 5651 break; 5652 5653 default: 5654 break; 5655 } 5656 5657 arg2 = prep_operand (arg2); 5658 arg3 = prep_operand (arg3); 5659 5660 if (code == COND_EXPR) 5661 /* Use build_conditional_expr instead. */ 5662 gcc_unreachable (); 5663 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1)) 5664 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2)))) 5665 goto builtin; 5666 5667 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR) 5668 arg2 = integer_zero_node; 5669 5670 vec_alloc (arglist, 3); 5671 arglist->quick_push (arg1); 5672 if (arg2 != NULL_TREE) 5673 arglist->quick_push (arg2); 5674 if (arg3 != NULL_TREE) 5675 arglist->quick_push (arg3); 5676 5677 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 5678 p = conversion_obstack_alloc (0); 5679 5680 /* Add namespace-scope operators to the list of functions to 5681 consider. */ 5682 if (!memonly) 5683 { 5684 tree fns = lookup_name_real (fnname, 0, 1, /*block_p=*/true, 0, 0); 5685 fns = lookup_arg_dependent (fnname, fns, arglist); 5686 add_candidates (fns, NULL_TREE, arglist, NULL_TREE, 5687 NULL_TREE, false, NULL_TREE, NULL_TREE, 5688 flags, &candidates, complain); 5689 } 5690 5691 args[0] = arg1; 5692 args[1] = arg2; 5693 args[2] = NULL_TREE; 5694 5695 /* Add class-member operators to the candidate set. */ 5696 if (CLASS_TYPE_P (TREE_TYPE (arg1))) 5697 { 5698 tree fns; 5699 5700 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1); 5701 if (fns == error_mark_node) 5702 { 5703 result = error_mark_node; 5704 goto user_defined_result_ready; 5705 } 5706 if (fns) 5707 add_candidates (BASELINK_FUNCTIONS (fns), 5708 NULL_TREE, arglist, NULL_TREE, 5709 NULL_TREE, false, 5710 BASELINK_BINFO (fns), 5711 BASELINK_ACCESS_BINFO (fns), 5712 flags, &candidates, complain); 5713 } 5714 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then 5715 only non-member functions that have type T1 or reference to 5716 cv-qualified-opt T1 for the first argument, if the first argument 5717 has an enumeration type, or T2 or reference to cv-qualified-opt 5718 T2 for the second argument, if the second argument has an 5719 enumeration type. Filter out those that don't match. */ 5720 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2))) 5721 { 5722 struct z_candidate **candp, **next; 5723 5724 for (candp = &candidates; *candp; candp = next) 5725 { 5726 tree parmlist, parmtype; 5727 int i, nargs = (arg2 ? 2 : 1); 5728 5729 cand = *candp; 5730 next = &cand->next; 5731 5732 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn)); 5733 5734 for (i = 0; i < nargs; ++i) 5735 { 5736 parmtype = TREE_VALUE (parmlist); 5737 5738 if (TREE_CODE (parmtype) == REFERENCE_TYPE) 5739 parmtype = TREE_TYPE (parmtype); 5740 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE 5741 && (same_type_ignoring_top_level_qualifiers_p 5742 (TREE_TYPE (args[i]), parmtype))) 5743 break; 5744 5745 parmlist = TREE_CHAIN (parmlist); 5746 } 5747 5748 /* No argument has an appropriate type, so remove this 5749 candidate function from the list. */ 5750 if (i == nargs) 5751 { 5752 *candp = cand->next; 5753 next = candp; 5754 } 5755 } 5756 } 5757 5758 add_builtin_candidates (&candidates, code, code2, fnname, args, 5759 flags, complain); 5760 5761 switch (code) 5762 { 5763 case COMPOUND_EXPR: 5764 case ADDR_EXPR: 5765 /* For these, the built-in candidates set is empty 5766 [over.match.oper]/3. We don't want non-strict matches 5767 because exact matches are always possible with built-in 5768 operators. The built-in candidate set for COMPONENT_REF 5769 would be empty too, but since there are no such built-in 5770 operators, we accept non-strict matches for them. */ 5771 strict_p = true; 5772 break; 5773 5774 default: 5775 strict_p = false; 5776 break; 5777 } 5778 5779 candidates = splice_viable (candidates, strict_p, &any_viable_p); 5780 if (!any_viable_p) 5781 { 5782 switch (code) 5783 { 5784 case POSTINCREMENT_EXPR: 5785 case POSTDECREMENT_EXPR: 5786 /* Don't try anything fancy if we're not allowed to produce 5787 errors. */ 5788 if (!(complain & tf_error)) 5789 return error_mark_node; 5790 5791 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't 5792 distinguish between prefix and postfix ++ and 5793 operator++() was used for both, so we allow this with 5794 -fpermissive. */ 5795 else 5796 { 5797 const char *msg = (flag_permissive) 5798 ? G_("no %<%D(int)%> declared for postfix %qs," 5799 " trying prefix operator instead") 5800 : G_("no %<%D(int)%> declared for postfix %qs"); 5801 permerror (loc, msg, fnname, OVL_OP_INFO (false, code)->name); 5802 } 5803 5804 if (!flag_permissive) 5805 return error_mark_node; 5806 5807 if (code == POSTINCREMENT_EXPR) 5808 code = PREINCREMENT_EXPR; 5809 else 5810 code = PREDECREMENT_EXPR; 5811 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE, 5812 NULL_TREE, overload, complain); 5813 break; 5814 5815 /* The caller will deal with these. */ 5816 case ADDR_EXPR: 5817 case COMPOUND_EXPR: 5818 case COMPONENT_REF: 5819 result = NULL_TREE; 5820 result_valid_p = true; 5821 break; 5822 5823 default: 5824 if (complain & tf_error) 5825 { 5826 /* If one of the arguments of the operator represents 5827 an invalid use of member function pointer, try to report 5828 a meaningful error ... */ 5829 if (invalid_nonstatic_memfn_p (loc, arg1, tf_error) 5830 || invalid_nonstatic_memfn_p (loc, arg2, tf_error) 5831 || invalid_nonstatic_memfn_p (loc, arg3, tf_error)) 5832 /* We displayed the error message. */; 5833 else 5834 { 5835 /* ... Otherwise, report the more generic 5836 "no matching operator found" error */ 5837 op_error (loc, code, code2, arg1, arg2, arg3, FALSE); 5838 print_z_candidates (loc, candidates); 5839 } 5840 } 5841 result = error_mark_node; 5842 break; 5843 } 5844 } 5845 else 5846 { 5847 cand = tourney (candidates, complain); 5848 if (cand == 0) 5849 { 5850 if (complain & tf_error) 5851 { 5852 op_error (loc, code, code2, arg1, arg2, arg3, TRUE); 5853 print_z_candidates (loc, candidates); 5854 } 5855 result = error_mark_node; 5856 } 5857 else if (TREE_CODE (cand->fn) == FUNCTION_DECL) 5858 { 5859 if (overload) 5860 *overload = cand->fn; 5861 5862 if (resolve_args (arglist, complain) == NULL) 5863 result = error_mark_node; 5864 else 5865 result = build_over_call (cand, LOOKUP_NORMAL, complain); 5866 5867 if (trivial_fn_p (cand->fn)) 5868 /* There won't be a CALL_EXPR. */; 5869 else if (result && result != error_mark_node) 5870 { 5871 tree call = extract_call_expr (result); 5872 CALL_EXPR_OPERATOR_SYNTAX (call) = true; 5873 5874 if (processing_template_decl && DECL_HIDDEN_FRIEND_P (cand->fn)) 5875 /* This prevents build_new_function_call from discarding this 5876 function during instantiation of the enclosing template. */ 5877 KOENIG_LOOKUP_P (call) = 1; 5878 5879 /* Specify evaluation order as per P0145R2. */ 5880 CALL_EXPR_ORDERED_ARGS (call) = false; 5881 switch (op_is_ordered (code)) 5882 { 5883 case -1: 5884 CALL_EXPR_REVERSE_ARGS (call) = true; 5885 break; 5886 5887 case 1: 5888 CALL_EXPR_ORDERED_ARGS (call) = true; 5889 break; 5890 5891 default: 5892 break; 5893 } 5894 } 5895 } 5896 else 5897 { 5898 /* Give any warnings we noticed during overload resolution. */ 5899 if (cand->warnings && (complain & tf_warning)) 5900 { 5901 struct candidate_warning *w; 5902 for (w = cand->warnings; w; w = w->next) 5903 joust (cand, w->loser, 1, complain); 5904 } 5905 5906 /* Check for comparison of different enum types. */ 5907 switch (code) 5908 { 5909 case GT_EXPR: 5910 case LT_EXPR: 5911 case GE_EXPR: 5912 case LE_EXPR: 5913 case EQ_EXPR: 5914 case NE_EXPR: 5915 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE 5916 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE 5917 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1)) 5918 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))) 5919 && (complain & tf_warning)) 5920 { 5921 warning (OPT_Wenum_compare, 5922 "comparison between %q#T and %q#T", 5923 TREE_TYPE (arg1), TREE_TYPE (arg2)); 5924 } 5925 break; 5926 default: 5927 break; 5928 } 5929 5930 /* We need to strip any leading REF_BIND so that bitfields 5931 don't cause errors. This should not remove any important 5932 conversions, because builtins don't apply to class 5933 objects directly. */ 5934 conv = cand->convs[0]; 5935 if (conv->kind == ck_ref_bind) 5936 conv = next_conversion (conv); 5937 arg1 = convert_like (conv, arg1, complain); 5938 5939 if (arg2) 5940 { 5941 conv = cand->convs[1]; 5942 if (conv->kind == ck_ref_bind) 5943 conv = next_conversion (conv); 5944 else 5945 arg2 = decay_conversion (arg2, complain); 5946 5947 /* We need to call warn_logical_operator before 5948 converting arg2 to a boolean_type, but after 5949 decaying an enumerator to its value. */ 5950 if (complain & tf_warning) 5951 warn_logical_operator (loc, code, boolean_type_node, 5952 code_orig_arg1, arg1, 5953 code_orig_arg2, arg2); 5954 5955 arg2 = convert_like (conv, arg2, complain); 5956 } 5957 if (arg3) 5958 { 5959 conv = cand->convs[2]; 5960 if (conv->kind == ck_ref_bind) 5961 conv = next_conversion (conv); 5962 arg3 = convert_like (conv, arg3, complain); 5963 } 5964 5965 } 5966 } 5967 5968 user_defined_result_ready: 5969 5970 /* Free all the conversions we allocated. */ 5971 obstack_free (&conversion_obstack, p); 5972 5973 if (result || result_valid_p) 5974 return result; 5975 5976 builtin: 5977 switch (code) 5978 { 5979 case MODIFY_EXPR: 5980 return cp_build_modify_expr (loc, arg1, code2, arg2, complain); 5981 5982 case INDIRECT_REF: 5983 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain); 5984 5985 case TRUTH_ANDIF_EXPR: 5986 case TRUTH_ORIF_EXPR: 5987 case TRUTH_AND_EXPR: 5988 case TRUTH_OR_EXPR: 5989 if (complain & tf_warning) 5990 warn_logical_operator (loc, code, boolean_type_node, 5991 code_orig_arg1, arg1, 5992 code_orig_arg2, arg2); 5993 /* Fall through. */ 5994 case GT_EXPR: 5995 case LT_EXPR: 5996 case GE_EXPR: 5997 case LE_EXPR: 5998 case EQ_EXPR: 5999 case NE_EXPR: 6000 if ((complain & tf_warning) 6001 && ((code_orig_arg1 == BOOLEAN_TYPE) 6002 ^ (code_orig_arg2 == BOOLEAN_TYPE))) 6003 maybe_warn_bool_compare (loc, code, arg1, arg2); 6004 if (complain & tf_warning && warn_tautological_compare) 6005 warn_tautological_cmp (loc, code, arg1, arg2); 6006 /* Fall through. */ 6007 case PLUS_EXPR: 6008 case MINUS_EXPR: 6009 case MULT_EXPR: 6010 case TRUNC_DIV_EXPR: 6011 case MAX_EXPR: 6012 case MIN_EXPR: 6013 case LSHIFT_EXPR: 6014 case RSHIFT_EXPR: 6015 case TRUNC_MOD_EXPR: 6016 case BIT_AND_EXPR: 6017 case BIT_IOR_EXPR: 6018 case BIT_XOR_EXPR: 6019 return cp_build_binary_op (loc, code, arg1, arg2, complain); 6020 6021 case UNARY_PLUS_EXPR: 6022 case NEGATE_EXPR: 6023 case BIT_NOT_EXPR: 6024 case TRUTH_NOT_EXPR: 6025 case PREINCREMENT_EXPR: 6026 case POSTINCREMENT_EXPR: 6027 case PREDECREMENT_EXPR: 6028 case POSTDECREMENT_EXPR: 6029 case REALPART_EXPR: 6030 case IMAGPART_EXPR: 6031 case ABS_EXPR: 6032 return cp_build_unary_op (code, arg1, candidates != 0, complain); 6033 6034 case ARRAY_REF: 6035 return cp_build_array_ref (input_location, arg1, arg2, complain); 6036 6037 case MEMBER_REF: 6038 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR, 6039 complain), 6040 arg2, complain); 6041 6042 /* The caller will deal with these. */ 6043 case ADDR_EXPR: 6044 case COMPONENT_REF: 6045 case COMPOUND_EXPR: 6046 return NULL_TREE; 6047 6048 default: 6049 gcc_unreachable (); 6050 } 6051 return NULL_TREE; 6052 } 6053 6054 /* Wrapper for above. */ 6055 6056 tree 6057 build_new_op (location_t loc, enum tree_code code, int flags, 6058 tree arg1, tree arg2, tree arg3, 6059 tree *overload, tsubst_flags_t complain) 6060 { 6061 tree ret; 6062 bool subtime = timevar_cond_start (TV_OVERLOAD); 6063 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3, 6064 overload, complain); 6065 timevar_cond_stop (TV_OVERLOAD, subtime); 6066 return ret; 6067 } 6068 6069 /* CALL was returned by some call-building function; extract the actual 6070 CALL_EXPR from any bits that have been tacked on, e.g. by 6071 convert_from_reference. */ 6072 6073 tree 6074 extract_call_expr (tree call) 6075 { 6076 while (TREE_CODE (call) == COMPOUND_EXPR) 6077 call = TREE_OPERAND (call, 1); 6078 if (REFERENCE_REF_P (call)) 6079 call = TREE_OPERAND (call, 0); 6080 if (TREE_CODE (call) == TARGET_EXPR) 6081 call = TARGET_EXPR_INITIAL (call); 6082 gcc_assert (TREE_CODE (call) == CALL_EXPR 6083 || TREE_CODE (call) == AGGR_INIT_EXPR 6084 || call == error_mark_node); 6085 return call; 6086 } 6087 6088 /* Returns true if FN has two parameters, of which the second has type 6089 size_t. */ 6090 6091 static bool 6092 second_parm_is_size_t (tree fn) 6093 { 6094 tree t = FUNCTION_ARG_CHAIN (fn); 6095 if (!t || !same_type_p (TREE_VALUE (t), size_type_node)) 6096 return false; 6097 t = TREE_CHAIN (t); 6098 if (t == void_list_node) 6099 return true; 6100 if (aligned_new_threshold && t 6101 && same_type_p (TREE_VALUE (t), align_type_node) 6102 && TREE_CHAIN (t) == void_list_node) 6103 return true; 6104 return false; 6105 } 6106 6107 /* True if T, an allocation function, has std::align_val_t as its second 6108 argument. */ 6109 6110 bool 6111 aligned_allocation_fn_p (tree t) 6112 { 6113 if (!aligned_new_threshold) 6114 return false; 6115 6116 tree a = FUNCTION_ARG_CHAIN (t); 6117 return (a && same_type_p (TREE_VALUE (a), align_type_node)); 6118 } 6119 6120 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation 6121 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of 6122 std::align_val_t. */ 6123 6124 static bool 6125 aligned_deallocation_fn_p (tree t) 6126 { 6127 if (!aligned_new_threshold) 6128 return false; 6129 6130 /* A template instance is never a usual deallocation function, 6131 regardless of its signature. */ 6132 if (TREE_CODE (t) == TEMPLATE_DECL 6133 || primary_template_specialization_p (t)) 6134 return false; 6135 6136 tree a = FUNCTION_ARG_CHAIN (t); 6137 if (same_type_p (TREE_VALUE (a), align_type_node) 6138 && TREE_CHAIN (a) == void_list_node) 6139 return true; 6140 if (!same_type_p (TREE_VALUE (a), size_type_node)) 6141 return false; 6142 a = TREE_CHAIN (a); 6143 if (a && same_type_p (TREE_VALUE (a), align_type_node) 6144 && TREE_CHAIN (a) == void_list_node) 6145 return true; 6146 return false; 6147 } 6148 6149 /* Returns true iff T, an element of an OVERLOAD chain, is a usual 6150 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */ 6151 6152 bool 6153 usual_deallocation_fn_p (tree t) 6154 { 6155 /* A template instance is never a usual deallocation function, 6156 regardless of its signature. */ 6157 if (TREE_CODE (t) == TEMPLATE_DECL 6158 || primary_template_specialization_p (t)) 6159 return false; 6160 6161 /* If a class T has a member deallocation function named operator delete 6162 with exactly one parameter, then that function is a usual 6163 (non-placement) deallocation function. If class T does not declare 6164 such an operator delete but does declare a member deallocation 6165 function named operator delete with exactly two parameters, the second 6166 of which has type std::size_t (18.2), then this function is a usual 6167 deallocation function. */ 6168 bool global = DECL_NAMESPACE_SCOPE_P (t); 6169 tree chain = FUNCTION_ARG_CHAIN (t); 6170 if (!chain) 6171 return false; 6172 if (chain == void_list_node 6173 || ((!global || flag_sized_deallocation) 6174 && second_parm_is_size_t (t))) 6175 return true; 6176 if (aligned_deallocation_fn_p (t)) 6177 return true; 6178 return false; 6179 } 6180 6181 /* Build a call to operator delete. This has to be handled very specially, 6182 because the restrictions on what signatures match are different from all 6183 other call instances. For a normal delete, only a delete taking (void *) 6184 or (void *, size_t) is accepted. For a placement delete, only an exact 6185 match with the placement new is accepted. 6186 6187 CODE is either DELETE_EXPR or VEC_DELETE_EXPR. 6188 ADDR is the pointer to be deleted. 6189 SIZE is the size of the memory block to be deleted. 6190 GLOBAL_P is true if the delete-expression should not consider 6191 class-specific delete operators. 6192 PLACEMENT is the corresponding placement new call, or NULL_TREE. 6193 6194 If this call to "operator delete" is being generated as part to 6195 deallocate memory allocated via a new-expression (as per [expr.new] 6196 which requires that if the initialization throws an exception then 6197 we call a deallocation function), then ALLOC_FN is the allocation 6198 function. */ 6199 6200 tree 6201 build_op_delete_call (enum tree_code code, tree addr, tree size, 6202 bool global_p, tree placement, 6203 tree alloc_fn, tsubst_flags_t complain) 6204 { 6205 tree fn = NULL_TREE; 6206 tree fns, fnname, type, t; 6207 6208 if (addr == error_mark_node) 6209 return error_mark_node; 6210 6211 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr))); 6212 6213 fnname = ovl_op_identifier (false, code); 6214 6215 if (CLASS_TYPE_P (type) 6216 && COMPLETE_TYPE_P (complete_type (type)) 6217 && !global_p) 6218 /* In [class.free] 6219 6220 If the result of the lookup is ambiguous or inaccessible, or if 6221 the lookup selects a placement deallocation function, the 6222 program is ill-formed. 6223 6224 Therefore, we ask lookup_fnfields to complain about ambiguity. */ 6225 { 6226 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1); 6227 if (fns == error_mark_node) 6228 return error_mark_node; 6229 } 6230 else 6231 fns = NULL_TREE; 6232 6233 if (fns == NULL_TREE) 6234 fns = lookup_name_nonclass (fnname); 6235 6236 /* Strip const and volatile from addr. */ 6237 addr = cp_convert (ptr_type_node, addr, complain); 6238 6239 if (placement) 6240 { 6241 /* "A declaration of a placement deallocation function matches the 6242 declaration of a placement allocation function if it has the same 6243 number of parameters and, after parameter transformations (8.3.5), 6244 all parameter types except the first are identical." 6245 6246 So we build up the function type we want and ask instantiate_type 6247 to get it for us. */ 6248 t = FUNCTION_ARG_CHAIN (alloc_fn); 6249 t = tree_cons (NULL_TREE, ptr_type_node, t); 6250 t = build_function_type (void_type_node, t); 6251 6252 fn = instantiate_type (t, fns, tf_none); 6253 if (fn == error_mark_node) 6254 return NULL_TREE; 6255 6256 fn = MAYBE_BASELINK_FUNCTIONS (fn); 6257 6258 /* "If the lookup finds the two-parameter form of a usual deallocation 6259 function (3.7.4.2) and that function, considered as a placement 6260 deallocation function, would have been selected as a match for the 6261 allocation function, the program is ill-formed." */ 6262 if (second_parm_is_size_t (fn)) 6263 { 6264 const char *const msg1 6265 = G_("exception cleanup for this placement new selects " 6266 "non-placement operator delete"); 6267 const char *const msg2 6268 = G_("%qD is a usual (non-placement) deallocation " 6269 "function in C++14 (or with -fsized-deallocation)"); 6270 6271 /* But if the class has an operator delete (void *), then that is 6272 the usual deallocation function, so we shouldn't complain 6273 about using the operator delete (void *, size_t). */ 6274 if (DECL_CLASS_SCOPE_P (fn)) 6275 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); 6276 iter; ++iter) 6277 { 6278 tree elt = *iter; 6279 if (usual_deallocation_fn_p (elt) 6280 && FUNCTION_ARG_CHAIN (elt) == void_list_node) 6281 goto ok; 6282 } 6283 /* Before C++14 a two-parameter global deallocation function is 6284 always a placement deallocation function, but warn if 6285 -Wc++14-compat. */ 6286 else if (!flag_sized_deallocation) 6287 { 6288 if ((complain & tf_warning) 6289 && warning (OPT_Wc__14_compat, msg1)) 6290 inform (DECL_SOURCE_LOCATION (fn), msg2, fn); 6291 goto ok; 6292 } 6293 6294 if (complain & tf_warning_or_error) 6295 { 6296 if (permerror (input_location, msg1)) 6297 { 6298 /* Only mention C++14 for namespace-scope delete. */ 6299 if (DECL_NAMESPACE_SCOPE_P (fn)) 6300 inform (DECL_SOURCE_LOCATION (fn), msg2, fn); 6301 else 6302 inform (DECL_SOURCE_LOCATION (fn), 6303 "%qD is a usual (non-placement) deallocation " 6304 "function", fn); 6305 } 6306 } 6307 else 6308 return error_mark_node; 6309 ok:; 6310 } 6311 } 6312 else 6313 /* "Any non-placement deallocation function matches a non-placement 6314 allocation function. If the lookup finds a single matching 6315 deallocation function, that function will be called; otherwise, no 6316 deallocation function will be called." */ 6317 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); iter; ++iter) 6318 { 6319 tree elt = *iter; 6320 if (usual_deallocation_fn_p (elt)) 6321 { 6322 if (!fn) 6323 { 6324 fn = elt; 6325 continue; 6326 } 6327 6328 /* -- If the type has new-extended alignment, a function with a 6329 parameter of type std::align_val_t is preferred; otherwise a 6330 function without such a parameter is preferred. If exactly one 6331 preferred function is found, that function is selected and the 6332 selection process terminates. If more than one preferred 6333 function is found, all non-preferred functions are eliminated 6334 from further consideration. */ 6335 if (aligned_new_threshold) 6336 { 6337 bool want_align = type_has_new_extended_alignment (type); 6338 bool fn_align = aligned_deallocation_fn_p (fn); 6339 bool elt_align = aligned_deallocation_fn_p (elt); 6340 6341 if (elt_align != fn_align) 6342 { 6343 if (want_align == elt_align) 6344 fn = elt; 6345 continue; 6346 } 6347 } 6348 6349 /* -- If the deallocation functions have class scope, the one 6350 without a parameter of type std::size_t is selected. */ 6351 bool want_size; 6352 if (DECL_CLASS_SCOPE_P (fn)) 6353 want_size = false; 6354 6355 /* -- If the type is complete and if, for the second alternative 6356 (delete array) only, the operand is a pointer to a class type 6357 with a non-trivial destructor or a (possibly multi-dimensional) 6358 array thereof, the function with a parameter of type std::size_t 6359 is selected. 6360 6361 -- Otherwise, it is unspecified whether a deallocation function 6362 with a parameter of type std::size_t is selected. */ 6363 else 6364 { 6365 want_size = COMPLETE_TYPE_P (type); 6366 if (code == VEC_DELETE_EXPR 6367 && !TYPE_VEC_NEW_USES_COOKIE (type)) 6368 /* We need a cookie to determine the array size. */ 6369 want_size = false; 6370 } 6371 bool fn_size = second_parm_is_size_t (fn); 6372 bool elt_size = second_parm_is_size_t (elt); 6373 gcc_assert (fn_size != elt_size); 6374 if (want_size == elt_size) 6375 fn = elt; 6376 } 6377 } 6378 6379 /* If we have a matching function, call it. */ 6380 if (fn) 6381 { 6382 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 6383 6384 /* If the FN is a member function, make sure that it is 6385 accessible. */ 6386 if (BASELINK_P (fns)) 6387 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn, 6388 complain); 6389 6390 /* Core issue 901: It's ok to new a type with deleted delete. */ 6391 if (DECL_DELETED_FN (fn) && alloc_fn) 6392 return NULL_TREE; 6393 6394 if (placement) 6395 { 6396 /* The placement args might not be suitable for overload 6397 resolution at this point, so build the call directly. */ 6398 int nargs = call_expr_nargs (placement); 6399 tree *argarray = XALLOCAVEC (tree, nargs); 6400 int i; 6401 argarray[0] = addr; 6402 for (i = 1; i < nargs; i++) 6403 argarray[i] = CALL_EXPR_ARG (placement, i); 6404 if (!mark_used (fn, complain) && !(complain & tf_error)) 6405 return error_mark_node; 6406 return build_cxx_call (fn, nargs, argarray, complain); 6407 } 6408 else 6409 { 6410 tree ret; 6411 vec<tree, va_gc> *args = make_tree_vector (); 6412 args->quick_push (addr); 6413 if (second_parm_is_size_t (fn)) 6414 args->quick_push (size); 6415 if (aligned_deallocation_fn_p (fn)) 6416 { 6417 tree al = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (type)); 6418 args->quick_push (al); 6419 } 6420 ret = cp_build_function_call_vec (fn, &args, complain); 6421 release_tree_vector (args); 6422 return ret; 6423 } 6424 } 6425 6426 /* [expr.new] 6427 6428 If no unambiguous matching deallocation function can be found, 6429 propagating the exception does not cause the object's memory to 6430 be freed. */ 6431 if (alloc_fn) 6432 { 6433 if ((complain & tf_warning) 6434 && !placement) 6435 warning (0, "no corresponding deallocation function for %qD", 6436 alloc_fn); 6437 return NULL_TREE; 6438 } 6439 6440 if (complain & tf_error) 6441 error ("no suitable %<operator %s%> for %qT", 6442 OVL_OP_INFO (false, code)->name, type); 6443 return error_mark_node; 6444 } 6445 6446 /* If the current scope isn't allowed to access DECL along 6447 BASETYPE_PATH, give an error. The most derived class in 6448 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is 6449 the declaration to use in the error diagnostic. */ 6450 6451 bool 6452 enforce_access (tree basetype_path, tree decl, tree diag_decl, 6453 tsubst_flags_t complain, access_failure_info *afi) 6454 { 6455 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO); 6456 6457 if (flag_new_inheriting_ctors 6458 && DECL_INHERITED_CTOR (decl)) 6459 { 6460 /* 7.3.3/18: The additional constructors are accessible if they would be 6461 accessible when used to construct an object of the corresponding base 6462 class. */ 6463 decl = strip_inheriting_ctors (decl); 6464 basetype_path = lookup_base (basetype_path, DECL_CONTEXT (decl), 6465 ba_any, NULL, complain); 6466 } 6467 6468 if (!accessible_p (basetype_path, decl, true)) 6469 { 6470 if (complain & tf_error) 6471 { 6472 if (flag_new_inheriting_ctors) 6473 diag_decl = strip_inheriting_ctors (diag_decl); 6474 if (TREE_PRIVATE (decl)) 6475 { 6476 error ("%q#D is private within this context", diag_decl); 6477 inform (DECL_SOURCE_LOCATION (diag_decl), 6478 "declared private here"); 6479 if (afi) 6480 afi->record_access_failure (basetype_path, diag_decl); 6481 } 6482 else if (TREE_PROTECTED (decl)) 6483 { 6484 error ("%q#D is protected within this context", diag_decl); 6485 inform (DECL_SOURCE_LOCATION (diag_decl), 6486 "declared protected here"); 6487 if (afi) 6488 afi->record_access_failure (basetype_path, diag_decl); 6489 } 6490 else 6491 { 6492 error ("%q#D is inaccessible within this context", diag_decl); 6493 inform (DECL_SOURCE_LOCATION (diag_decl), "declared here"); 6494 if (afi) 6495 afi->record_access_failure (basetype_path, diag_decl); 6496 } 6497 } 6498 return false; 6499 } 6500 6501 return true; 6502 } 6503 6504 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a 6505 bitwise or of LOOKUP_* values. If any errors are warnings are 6506 generated, set *DIAGNOSTIC_FN to "error" or "warning", 6507 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN 6508 to NULL. */ 6509 6510 static tree 6511 build_temp (tree expr, tree type, int flags, 6512 diagnostic_t *diagnostic_kind, tsubst_flags_t complain) 6513 { 6514 int savew, savee; 6515 vec<tree, va_gc> *args; 6516 6517 *diagnostic_kind = DK_UNSPECIFIED; 6518 6519 /* If the source is a packed field, calling the copy constructor will require 6520 binding the field to the reference parameter to the copy constructor, and 6521 we'll end up with an infinite loop. If we can use a bitwise copy, then 6522 do that now. */ 6523 if ((lvalue_kind (expr) & clk_packed) 6524 && CLASS_TYPE_P (TREE_TYPE (expr)) 6525 && !type_has_nontrivial_copy_init (TREE_TYPE (expr))) 6526 return get_target_expr_sfinae (expr, complain); 6527 6528 savew = warningcount + werrorcount, savee = errorcount; 6529 args = make_tree_vector_single (expr); 6530 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 6531 &args, type, flags, complain); 6532 release_tree_vector (args); 6533 if (warningcount + werrorcount > savew) 6534 *diagnostic_kind = DK_WARNING; 6535 else if (errorcount > savee) 6536 *diagnostic_kind = DK_ERROR; 6537 return expr; 6538 } 6539 6540 /* Perform warnings about peculiar, but valid, conversions from/to NULL. 6541 EXPR is implicitly converted to type TOTYPE. 6542 FN and ARGNUM are used for diagnostics. */ 6543 6544 static void 6545 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum) 6546 { 6547 /* Issue warnings about peculiar, but valid, uses of NULL. */ 6548 if (null_node_p (expr) && TREE_CODE (totype) != BOOLEAN_TYPE 6549 && ARITHMETIC_TYPE_P (totype)) 6550 { 6551 source_location loc = 6552 expansion_point_location_if_in_system_header (input_location); 6553 6554 if (fn) 6555 warning_at (loc, OPT_Wconversion_null, 6556 "passing NULL to non-pointer argument %P of %qD", 6557 argnum, fn); 6558 else 6559 warning_at (loc, OPT_Wconversion_null, 6560 "converting to non-pointer type %qT from NULL", totype); 6561 } 6562 6563 /* Issue warnings if "false" is converted to a NULL pointer */ 6564 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE 6565 && TYPE_PTR_P (totype)) 6566 { 6567 if (fn) 6568 warning_at (input_location, OPT_Wconversion_null, 6569 "converting %<false%> to pointer type for argument %P " 6570 "of %qD", argnum, fn); 6571 else 6572 warning_at (input_location, OPT_Wconversion_null, 6573 "converting %<false%> to pointer type %qT", totype); 6574 } 6575 } 6576 6577 /* We gave a diagnostic during a conversion. If this was in the second 6578 standard conversion sequence of a user-defined conversion sequence, say 6579 which user-defined conversion. */ 6580 6581 static void 6582 maybe_print_user_conv_context (conversion *convs) 6583 { 6584 if (convs->user_conv_p) 6585 for (conversion *t = convs; t; t = next_conversion (t)) 6586 if (t->kind == ck_user) 6587 { 6588 print_z_candidate (0, " after user-defined conversion:", 6589 t->cand); 6590 break; 6591 } 6592 } 6593 6594 /* Locate the parameter with the given index within FNDECL. 6595 ARGNUM is zero based, -1 indicates the `this' argument of a method. 6596 Return the location of the FNDECL itself if there are problems. */ 6597 6598 location_t 6599 get_fndecl_argument_location (tree fndecl, int argnum) 6600 { 6601 int i; 6602 tree param; 6603 6604 /* Locate param by index within DECL_ARGUMENTS (fndecl). */ 6605 for (i = 0, param = FUNCTION_FIRST_USER_PARM (fndecl); 6606 i < argnum && param; 6607 i++, param = TREE_CHAIN (param)) 6608 ; 6609 6610 /* If something went wrong (e.g. if we have a builtin and thus no arguments), 6611 return the location of FNDECL. */ 6612 if (param == NULL) 6613 return DECL_SOURCE_LOCATION (fndecl); 6614 6615 return DECL_SOURCE_LOCATION (param); 6616 } 6617 6618 /* Perform the conversions in CONVS on the expression EXPR. FN and 6619 ARGNUM are used for diagnostics. ARGNUM is zero based, -1 6620 indicates the `this' argument of a method. INNER is nonzero when 6621 being called to continue a conversion chain. It is negative when a 6622 reference binding will be applied, positive otherwise. If 6623 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious 6624 conversions will be emitted if appropriate. If C_CAST_P is true, 6625 this conversion is coming from a C-style cast; in that case, 6626 conversions to inaccessible bases are permitted. */ 6627 6628 static tree 6629 convert_like_real (conversion *convs, tree expr, tree fn, int argnum, 6630 bool issue_conversion_warnings, 6631 bool c_cast_p, tsubst_flags_t complain) 6632 { 6633 tree totype = convs->type; 6634 diagnostic_t diag_kind; 6635 int flags; 6636 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 6637 6638 if (convs->bad_p && !(complain & tf_error)) 6639 return error_mark_node; 6640 6641 if (convs->bad_p 6642 && convs->kind != ck_user 6643 && convs->kind != ck_list 6644 && convs->kind != ck_ambig 6645 && (convs->kind != ck_ref_bind 6646 || (convs->user_conv_p && next_conversion (convs)->bad_p)) 6647 && (convs->kind != ck_rvalue 6648 || SCALAR_TYPE_P (totype)) 6649 && convs->kind != ck_base) 6650 { 6651 bool complained = false; 6652 conversion *t = convs; 6653 6654 /* Give a helpful error if this is bad because of excess braces. */ 6655 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 6656 && SCALAR_TYPE_P (totype) 6657 && CONSTRUCTOR_NELTS (expr) > 0 6658 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value)) 6659 { 6660 complained = permerror (loc, "too many braces around initializer " 6661 "for %qT", totype); 6662 while (BRACE_ENCLOSED_INITIALIZER_P (expr) 6663 && CONSTRUCTOR_NELTS (expr) == 1) 6664 expr = CONSTRUCTOR_ELT (expr, 0)->value; 6665 } 6666 6667 /* Give a helpful error if this is bad because a conversion to bool 6668 from std::nullptr_t requires direct-initialization. */ 6669 if (NULLPTR_TYPE_P (TREE_TYPE (expr)) 6670 && TREE_CODE (totype) == BOOLEAN_TYPE) 6671 complained = permerror (loc, "converting to %qH from %qI requires " 6672 "direct-initialization", 6673 totype, TREE_TYPE (expr)); 6674 6675 for (; t ; t = next_conversion (t)) 6676 { 6677 if (t->kind == ck_user && t->cand->reason) 6678 { 6679 complained = permerror (loc, "invalid user-defined conversion " 6680 "from %qH to %qI", TREE_TYPE (expr), 6681 totype); 6682 if (complained) 6683 print_z_candidate (loc, "candidate is:", t->cand); 6684 expr = convert_like_real (t, expr, fn, argnum, 6685 /*issue_conversion_warnings=*/false, 6686 /*c_cast_p=*/false, 6687 complain); 6688 if (convs->kind == ck_ref_bind) 6689 expr = convert_to_reference (totype, expr, CONV_IMPLICIT, 6690 LOOKUP_NORMAL, NULL_TREE, 6691 complain); 6692 else 6693 expr = cp_convert (totype, expr, complain); 6694 if (complained && fn) 6695 inform (DECL_SOURCE_LOCATION (fn), 6696 " initializing argument %P of %qD", argnum, fn); 6697 return expr; 6698 } 6699 else if (t->kind == ck_user || !t->bad_p) 6700 { 6701 expr = convert_like_real (t, expr, fn, argnum, 6702 /*issue_conversion_warnings=*/false, 6703 /*c_cast_p=*/false, 6704 complain); 6705 break; 6706 } 6707 else if (t->kind == ck_ambig) 6708 return convert_like_real (t, expr, fn, argnum, 6709 /*issue_conversion_warnings=*/false, 6710 /*c_cast_p=*/false, 6711 complain); 6712 else if (t->kind == ck_identity) 6713 break; 6714 } 6715 if (!complained) 6716 complained = permerror (loc, "invalid conversion from %qH to %qI", 6717 TREE_TYPE (expr), totype); 6718 if (complained && fn) 6719 inform (get_fndecl_argument_location (fn, argnum), 6720 " initializing argument %P of %qD", argnum, fn); 6721 6722 return cp_convert (totype, expr, complain); 6723 } 6724 6725 if (issue_conversion_warnings && (complain & tf_warning)) 6726 conversion_null_warnings (totype, expr, fn, argnum); 6727 6728 switch (convs->kind) 6729 { 6730 case ck_user: 6731 { 6732 struct z_candidate *cand = convs->cand; 6733 6734 if (cand == NULL) 6735 /* We chose the surrogate function from add_conv_candidate, now we 6736 actually need to build the conversion. */ 6737 cand = build_user_type_conversion_1 (totype, expr, 6738 LOOKUP_NO_CONVERSION, complain); 6739 6740 tree convfn = cand->fn; 6741 6742 /* When converting from an init list we consider explicit 6743 constructors, but actually trying to call one is an error. */ 6744 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn) 6745 && BRACE_ENCLOSED_INITIALIZER_P (expr) 6746 /* Unless this is for direct-list-initialization. */ 6747 && !CONSTRUCTOR_IS_DIRECT_INIT (expr) 6748 /* And in C++98 a default constructor can't be explicit. */ 6749 && cxx_dialect >= cxx11) 6750 { 6751 if (!(complain & tf_error)) 6752 return error_mark_node; 6753 location_t loc = location_of (expr); 6754 if (CONSTRUCTOR_NELTS (expr) == 0 6755 && FUNCTION_FIRST_USER_PARMTYPE (convfn) != void_list_node) 6756 { 6757 if (pedwarn (loc, 0, "converting to %qT from initializer list " 6758 "would use explicit constructor %qD", 6759 totype, convfn)) 6760 inform (loc, "in C++11 and above a default constructor " 6761 "can be explicit"); 6762 } 6763 else 6764 error ("converting to %qT from initializer list would use " 6765 "explicit constructor %qD", totype, convfn); 6766 } 6767 6768 /* If we're initializing from {}, it's value-initialization. */ 6769 if (BRACE_ENCLOSED_INITIALIZER_P (expr) 6770 && CONSTRUCTOR_NELTS (expr) == 0 6771 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)) 6772 { 6773 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr); 6774 if (abstract_virtuals_error_sfinae (NULL_TREE, totype, complain)) 6775 return error_mark_node; 6776 expr = build_value_init (totype, complain); 6777 expr = get_target_expr_sfinae (expr, complain); 6778 if (expr != error_mark_node) 6779 { 6780 TARGET_EXPR_LIST_INIT_P (expr) = true; 6781 TARGET_EXPR_DIRECT_INIT_P (expr) = direct; 6782 } 6783 return expr; 6784 } 6785 6786 expr = mark_rvalue_use (expr); 6787 6788 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow 6789 any more UDCs. */ 6790 expr = build_over_call (cand, LOOKUP_NORMAL|LOOKUP_NO_CONVERSION, 6791 complain); 6792 6793 /* If this is a constructor or a function returning an aggr type, 6794 we need to build up a TARGET_EXPR. */ 6795 if (DECL_CONSTRUCTOR_P (convfn)) 6796 { 6797 expr = build_cplus_new (totype, expr, complain); 6798 6799 /* Remember that this was list-initialization. */ 6800 if (convs->check_narrowing && expr != error_mark_node) 6801 TARGET_EXPR_LIST_INIT_P (expr) = true; 6802 } 6803 6804 return expr; 6805 } 6806 case ck_identity: 6807 if (BRACE_ENCLOSED_INITIALIZER_P (expr)) 6808 { 6809 int nelts = CONSTRUCTOR_NELTS (expr); 6810 if (nelts == 0) 6811 expr = build_value_init (totype, complain); 6812 else if (nelts == 1) 6813 expr = CONSTRUCTOR_ELT (expr, 0)->value; 6814 else 6815 gcc_unreachable (); 6816 } 6817 expr = mark_use (expr, /*rvalue_p=*/!convs->rvaluedness_matches_p, 6818 /*read_p=*/true, UNKNOWN_LOCATION, 6819 /*reject_builtin=*/true); 6820 6821 if (type_unknown_p (expr)) 6822 expr = instantiate_type (totype, expr, complain); 6823 if (expr == null_node 6824 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype)) 6825 /* If __null has been converted to an integer type, we do not want to 6826 continue to warn about uses of EXPR as an integer, rather than as a 6827 pointer. */ 6828 expr = build_int_cst (totype, 0); 6829 return expr; 6830 case ck_ambig: 6831 /* We leave bad_p off ck_ambig because overload resolution considers 6832 it valid, it just fails when we try to perform it. So we need to 6833 check complain here, too. */ 6834 if (complain & tf_error) 6835 { 6836 /* Call build_user_type_conversion again for the error. */ 6837 int flags = (convs->need_temporary_p 6838 ? LOOKUP_IMPLICIT : LOOKUP_NORMAL); 6839 build_user_type_conversion (totype, convs->u.expr, flags, complain); 6840 gcc_assert (seen_error ()); 6841 if (fn) 6842 inform (DECL_SOURCE_LOCATION (fn), 6843 " initializing argument %P of %qD", argnum, fn); 6844 } 6845 return error_mark_node; 6846 6847 case ck_list: 6848 { 6849 /* Conversion to std::initializer_list<T>. */ 6850 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0); 6851 tree new_ctor = build_constructor (init_list_type_node, NULL); 6852 unsigned len = CONSTRUCTOR_NELTS (expr); 6853 tree array, val, field; 6854 vec<constructor_elt, va_gc> *vec = NULL; 6855 unsigned ix; 6856 6857 /* Convert all the elements. */ 6858 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val) 6859 { 6860 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum, 6861 false, false, complain); 6862 if (sub == error_mark_node) 6863 return sub; 6864 if (!BRACE_ENCLOSED_INITIALIZER_P (val) 6865 && !check_narrowing (TREE_TYPE (sub), val, complain)) 6866 return error_mark_node; 6867 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub); 6868 if (!TREE_CONSTANT (sub)) 6869 TREE_CONSTANT (new_ctor) = false; 6870 } 6871 /* Build up the array. */ 6872 elttype = cp_build_qualified_type 6873 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST); 6874 array = build_array_of_n_type (elttype, len); 6875 array = finish_compound_literal (array, new_ctor, complain); 6876 /* Take the address explicitly rather than via decay_conversion 6877 to avoid the error about taking the address of a temporary. */ 6878 array = cp_build_addr_expr (array, complain); 6879 array = cp_convert (build_pointer_type (elttype), array, complain); 6880 if (array == error_mark_node) 6881 return error_mark_node; 6882 6883 /* Build up the initializer_list object. Note: fail gracefully 6884 if the object cannot be completed because, for example, no 6885 definition is provided (c++/80956). */ 6886 totype = complete_type_or_maybe_complain (totype, NULL_TREE, complain); 6887 if (!totype) 6888 return error_mark_node; 6889 field = next_initializable_field (TYPE_FIELDS (totype)); 6890 CONSTRUCTOR_APPEND_ELT (vec, field, array); 6891 field = next_initializable_field (DECL_CHAIN (field)); 6892 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len)); 6893 new_ctor = build_constructor (totype, vec); 6894 return get_target_expr_sfinae (new_ctor, complain); 6895 } 6896 6897 case ck_aggr: 6898 if (TREE_CODE (totype) == COMPLEX_TYPE) 6899 { 6900 tree real = CONSTRUCTOR_ELT (expr, 0)->value; 6901 tree imag = CONSTRUCTOR_ELT (expr, 1)->value; 6902 real = perform_implicit_conversion (TREE_TYPE (totype), 6903 real, complain); 6904 imag = perform_implicit_conversion (TREE_TYPE (totype), 6905 imag, complain); 6906 expr = build2 (COMPLEX_EXPR, totype, real, imag); 6907 return expr; 6908 } 6909 expr = reshape_init (totype, expr, complain); 6910 expr = get_target_expr_sfinae (digest_init (totype, expr, complain), 6911 complain); 6912 if (expr != error_mark_node) 6913 TARGET_EXPR_LIST_INIT_P (expr) = true; 6914 return expr; 6915 6916 default: 6917 break; 6918 }; 6919 6920 expr = convert_like_real (next_conversion (convs), expr, fn, argnum, 6921 convs->kind == ck_ref_bind 6922 ? issue_conversion_warnings : false, 6923 c_cast_p, complain); 6924 if (expr == error_mark_node) 6925 return error_mark_node; 6926 6927 switch (convs->kind) 6928 { 6929 case ck_rvalue: 6930 expr = decay_conversion (expr, complain); 6931 if (expr == error_mark_node) 6932 { 6933 if (complain & tf_error) 6934 { 6935 maybe_print_user_conv_context (convs); 6936 if (fn) 6937 inform (DECL_SOURCE_LOCATION (fn), 6938 " initializing argument %P of %qD", argnum, fn); 6939 } 6940 return error_mark_node; 6941 } 6942 6943 if (! MAYBE_CLASS_TYPE_P (totype)) 6944 return expr; 6945 6946 /* Don't introduce copies when passing arguments along to the inherited 6947 constructor. */ 6948 if (current_function_decl 6949 && flag_new_inheriting_ctors 6950 && DECL_INHERITED_CTOR (current_function_decl)) 6951 return expr; 6952 6953 if (TREE_CODE (expr) == TARGET_EXPR 6954 && TARGET_EXPR_LIST_INIT_P (expr)) 6955 /* Copy-list-initialization doesn't actually involve a copy. */ 6956 return expr; 6957 6958 /* Fall through. */ 6959 case ck_base: 6960 if (convs->kind == ck_base && !convs->need_temporary_p) 6961 { 6962 /* We are going to bind a reference directly to a base-class 6963 subobject of EXPR. */ 6964 /* Build an expression for `*((base*) &expr)'. */ 6965 expr = convert_to_base (expr, totype, 6966 !c_cast_p, /*nonnull=*/true, complain); 6967 return expr; 6968 } 6969 6970 /* Copy-initialization where the cv-unqualified version of the source 6971 type is the same class as, or a derived class of, the class of the 6972 destination [is treated as direct-initialization]. [dcl.init] */ 6973 flags = LOOKUP_NORMAL; 6974 if (convs->user_conv_p) 6975 /* This conversion is being done in the context of a user-defined 6976 conversion (i.e. the second step of copy-initialization), so 6977 don't allow any more. */ 6978 flags |= LOOKUP_NO_CONVERSION; 6979 else 6980 flags |= LOOKUP_ONLYCONVERTING; 6981 if (convs->rvaluedness_matches_p) 6982 /* standard_conversion got LOOKUP_PREFER_RVALUE. */ 6983 flags |= LOOKUP_PREFER_RVALUE; 6984 expr = build_temp (expr, totype, flags, &diag_kind, complain); 6985 if (diag_kind && complain) 6986 { 6987 maybe_print_user_conv_context (convs); 6988 if (fn) 6989 inform (DECL_SOURCE_LOCATION (fn), 6990 " initializing argument %P of %qD", argnum, fn); 6991 } 6992 6993 return build_cplus_new (totype, expr, complain); 6994 6995 case ck_ref_bind: 6996 { 6997 tree ref_type = totype; 6998 6999 if (convs->bad_p && !next_conversion (convs)->bad_p) 7000 { 7001 tree extype = TREE_TYPE (expr); 7002 if (TYPE_REF_IS_RVALUE (ref_type) 7003 && lvalue_p (expr)) 7004 error_at (loc, "cannot bind rvalue reference of type %qH to " 7005 "lvalue of type %qI", totype, extype); 7006 else if (!TYPE_REF_IS_RVALUE (ref_type) && !lvalue_p (expr) 7007 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))) 7008 error_at (loc, "cannot bind non-const lvalue reference of " 7009 "type %qH to an rvalue of type %qI", totype, extype); 7010 else if (!reference_compatible_p (TREE_TYPE (totype), extype)) 7011 error_at (loc, "binding reference of type %qH to %qI " 7012 "discards qualifiers", totype, extype); 7013 else 7014 gcc_unreachable (); 7015 maybe_print_user_conv_context (convs); 7016 if (fn) 7017 inform (DECL_SOURCE_LOCATION (fn), 7018 " initializing argument %P of %qD", argnum, fn); 7019 return error_mark_node; 7020 } 7021 7022 /* If necessary, create a temporary. 7023 7024 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases 7025 that need temporaries, even when their types are reference 7026 compatible with the type of reference being bound, so the 7027 upcoming call to cp_build_addr_expr doesn't fail. */ 7028 if (convs->need_temporary_p 7029 || TREE_CODE (expr) == CONSTRUCTOR 7030 || TREE_CODE (expr) == VA_ARG_EXPR) 7031 { 7032 /* Otherwise, a temporary of type "cv1 T1" is created and 7033 initialized from the initializer expression using the rules 7034 for a non-reference copy-initialization (8.5). */ 7035 7036 tree type = TREE_TYPE (ref_type); 7037 cp_lvalue_kind lvalue = lvalue_kind (expr); 7038 7039 gcc_assert (same_type_ignoring_top_level_qualifiers_p 7040 (type, next_conversion (convs)->type)); 7041 if (!CP_TYPE_CONST_NON_VOLATILE_P (type) 7042 && !TYPE_REF_IS_RVALUE (ref_type)) 7043 { 7044 /* If the reference is volatile or non-const, we 7045 cannot create a temporary. */ 7046 if (lvalue & clk_bitfield) 7047 error_at (loc, "cannot bind bitfield %qE to %qT", 7048 expr, ref_type); 7049 else if (lvalue & clk_packed) 7050 error_at (loc, "cannot bind packed field %qE to %qT", 7051 expr, ref_type); 7052 else 7053 error_at (loc, "cannot bind rvalue %qE to %qT", 7054 expr, ref_type); 7055 return error_mark_node; 7056 } 7057 /* If the source is a packed field, and we must use a copy 7058 constructor, then building the target expr will require 7059 binding the field to the reference parameter to the 7060 copy constructor, and we'll end up with an infinite 7061 loop. If we can use a bitwise copy, then we'll be 7062 OK. */ 7063 if ((lvalue & clk_packed) 7064 && CLASS_TYPE_P (type) 7065 && type_has_nontrivial_copy_init (type)) 7066 { 7067 error_at (loc, "cannot bind packed field %qE to %qT", 7068 expr, ref_type); 7069 return error_mark_node; 7070 } 7071 if (lvalue & clk_bitfield) 7072 { 7073 expr = convert_bitfield_to_declared_type (expr); 7074 expr = fold_convert (type, expr); 7075 } 7076 expr = build_target_expr_with_type (expr, type, complain); 7077 } 7078 7079 /* Take the address of the thing to which we will bind the 7080 reference. */ 7081 expr = cp_build_addr_expr (expr, complain); 7082 if (expr == error_mark_node) 7083 return error_mark_node; 7084 7085 /* Convert it to a pointer to the type referred to by the 7086 reference. This will adjust the pointer if a derived to 7087 base conversion is being performed. */ 7088 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)), 7089 expr, complain); 7090 /* Convert the pointer to the desired reference type. */ 7091 return build_nop (ref_type, expr); 7092 } 7093 7094 case ck_lvalue: 7095 return decay_conversion (expr, complain); 7096 7097 case ck_fnptr: 7098 /* ??? Should the address of a transaction-safe pointer point to the TM 7099 clone, and this conversion look up the primary function? */ 7100 return build_nop (totype, expr); 7101 7102 case ck_qual: 7103 /* Warn about deprecated conversion if appropriate. */ 7104 string_conv_p (totype, expr, 1); 7105 break; 7106 7107 case ck_ptr: 7108 if (convs->base_p) 7109 expr = convert_to_base (expr, totype, !c_cast_p, 7110 /*nonnull=*/false, complain); 7111 return build_nop (totype, expr); 7112 7113 case ck_pmem: 7114 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false, 7115 c_cast_p, complain); 7116 7117 default: 7118 break; 7119 } 7120 7121 if (convs->check_narrowing 7122 && !check_narrowing (totype, expr, complain)) 7123 return error_mark_node; 7124 7125 if (issue_conversion_warnings) 7126 expr = cp_convert_and_check (totype, expr, complain); 7127 else 7128 expr = cp_convert (totype, expr, complain); 7129 7130 return expr; 7131 } 7132 7133 /* ARG is being passed to a varargs function. Perform any conversions 7134 required. Return the converted value. */ 7135 7136 tree 7137 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain) 7138 { 7139 tree arg_type; 7140 location_t loc = EXPR_LOC_OR_LOC (arg, input_location); 7141 7142 /* [expr.call] 7143 7144 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer 7145 standard conversions are performed. */ 7146 arg = decay_conversion (arg, complain); 7147 arg_type = TREE_TYPE (arg); 7148 /* [expr.call] 7149 7150 If the argument has integral or enumeration type that is subject 7151 to the integral promotions (_conv.prom_), or a floating point 7152 type that is subject to the floating point promotion 7153 (_conv.fpprom_), the value of the argument is converted to the 7154 promoted type before the call. */ 7155 if (TREE_CODE (arg_type) == REAL_TYPE 7156 && (TYPE_PRECISION (arg_type) 7157 < TYPE_PRECISION (double_type_node)) 7158 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type))) 7159 { 7160 if ((complain & tf_warning) 7161 && warn_double_promotion && !c_inhibit_evaluation_warnings) 7162 warning_at (loc, OPT_Wdouble_promotion, 7163 "implicit conversion from %qH to %qI when passing " 7164 "argument to function", 7165 arg_type, double_type_node); 7166 arg = convert_to_real_nofold (double_type_node, arg); 7167 } 7168 else if (NULLPTR_TYPE_P (arg_type)) 7169 arg = null_pointer_node; 7170 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type)) 7171 { 7172 if (SCOPED_ENUM_P (arg_type)) 7173 { 7174 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg, 7175 complain); 7176 prom = cp_perform_integral_promotions (prom, complain); 7177 if (abi_version_crosses (6) 7178 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type) 7179 && (complain & tf_warning)) 7180 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as " 7181 "%qT before -fabi-version=6, %qT after", arg_type, 7182 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type)); 7183 if (!abi_version_at_least (6)) 7184 arg = prom; 7185 } 7186 else 7187 arg = cp_perform_integral_promotions (arg, complain); 7188 } 7189 7190 arg = require_complete_type_sfinae (arg, complain); 7191 arg_type = TREE_TYPE (arg); 7192 7193 if (arg != error_mark_node 7194 /* In a template (or ill-formed code), we can have an incomplete type 7195 even after require_complete_type_sfinae, in which case we don't know 7196 whether it has trivial copy or not. */ 7197 && COMPLETE_TYPE_P (arg_type) 7198 && !cp_unevaluated_operand) 7199 { 7200 /* [expr.call] 5.2.2/7: 7201 Passing a potentially-evaluated argument of class type (Clause 9) 7202 with a non-trivial copy constructor or a non-trivial destructor 7203 with no corresponding parameter is conditionally-supported, with 7204 implementation-defined semantics. 7205 7206 We support it as pass-by-invisible-reference, just like a normal 7207 value parameter. 7208 7209 If the call appears in the context of a sizeof expression, 7210 it is not potentially-evaluated. */ 7211 if (type_has_nontrivial_copy_init (arg_type) 7212 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)) 7213 { 7214 arg = force_rvalue (arg, complain); 7215 if (complain & tf_warning) 7216 warning (OPT_Wconditionally_supported, 7217 "passing objects of non-trivially-copyable " 7218 "type %q#T through %<...%> is conditionally supported", 7219 arg_type); 7220 return build1 (ADDR_EXPR, build_reference_type (arg_type), arg); 7221 } 7222 /* Build up a real lvalue-to-rvalue conversion in case the 7223 copy constructor is trivial but not callable. */ 7224 else if (CLASS_TYPE_P (arg_type)) 7225 force_rvalue (arg, complain); 7226 7227 } 7228 7229 return arg; 7230 } 7231 7232 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */ 7233 7234 tree 7235 build_x_va_arg (source_location loc, tree expr, tree type) 7236 { 7237 if (processing_template_decl) 7238 { 7239 tree r = build_min (VA_ARG_EXPR, type, expr); 7240 SET_EXPR_LOCATION (r, loc); 7241 return r; 7242 } 7243 7244 type = complete_type_or_else (type, NULL_TREE); 7245 7246 if (expr == error_mark_node || !type) 7247 return error_mark_node; 7248 7249 expr = mark_lvalue_use (expr); 7250 7251 if (TREE_CODE (type) == REFERENCE_TYPE) 7252 { 7253 error ("cannot receive reference type %qT through %<...%>", type); 7254 return error_mark_node; 7255 } 7256 7257 if (type_has_nontrivial_copy_init (type) 7258 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 7259 { 7260 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat 7261 it as pass by invisible reference. */ 7262 warning_at (loc, OPT_Wconditionally_supported, 7263 "receiving objects of non-trivially-copyable type %q#T " 7264 "through %<...%> is conditionally-supported", type); 7265 7266 tree ref = cp_build_reference_type (type, false); 7267 expr = build_va_arg (loc, expr, ref); 7268 return convert_from_reference (expr); 7269 } 7270 7271 tree ret = build_va_arg (loc, expr, type); 7272 if (CLASS_TYPE_P (type)) 7273 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to 7274 know how to handle it. */ 7275 ret = get_target_expr (ret); 7276 return ret; 7277 } 7278 7279 /* TYPE has been given to va_arg. Apply the default conversions which 7280 would have happened when passed via ellipsis. Return the promoted 7281 type, or the passed type if there is no change. */ 7282 7283 tree 7284 cxx_type_promotes_to (tree type) 7285 { 7286 tree promote; 7287 7288 /* Perform the array-to-pointer and function-to-pointer 7289 conversions. */ 7290 type = type_decays_to (type); 7291 7292 promote = type_promotes_to (type); 7293 if (same_type_p (type, promote)) 7294 promote = type; 7295 7296 return promote; 7297 } 7298 7299 /* ARG is a default argument expression being passed to a parameter of 7300 the indicated TYPE, which is a parameter to FN. PARMNUM is the 7301 zero-based argument number. Do any required conversions. Return 7302 the converted value. */ 7303 7304 static GTY(()) vec<tree, va_gc> *default_arg_context; 7305 void 7306 push_defarg_context (tree fn) 7307 { vec_safe_push (default_arg_context, fn); } 7308 7309 void 7310 pop_defarg_context (void) 7311 { default_arg_context->pop (); } 7312 7313 tree 7314 convert_default_arg (tree type, tree arg, tree fn, int parmnum, 7315 tsubst_flags_t complain) 7316 { 7317 int i; 7318 tree t; 7319 7320 /* See through clones. */ 7321 fn = DECL_ORIGIN (fn); 7322 /* And inheriting ctors. */ 7323 if (flag_new_inheriting_ctors) 7324 fn = strip_inheriting_ctors (fn); 7325 7326 /* Detect recursion. */ 7327 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t) 7328 if (t == fn) 7329 { 7330 if (complain & tf_error) 7331 error ("recursive evaluation of default argument for %q#D", fn); 7332 return error_mark_node; 7333 } 7334 7335 /* If the ARG is an unparsed default argument expression, the 7336 conversion cannot be performed. */ 7337 if (TREE_CODE (arg) == DEFAULT_ARG) 7338 { 7339 if (complain & tf_error) 7340 error ("call to %qD uses the default argument for parameter %P, which " 7341 "is not yet defined", fn, parmnum); 7342 return error_mark_node; 7343 } 7344 7345 push_defarg_context (fn); 7346 7347 if (fn && DECL_TEMPLATE_INFO (fn)) 7348 arg = tsubst_default_argument (fn, parmnum, type, arg, complain); 7349 7350 /* Due to: 7351 7352 [dcl.fct.default] 7353 7354 The names in the expression are bound, and the semantic 7355 constraints are checked, at the point where the default 7356 expressions appears. 7357 7358 we must not perform access checks here. */ 7359 push_deferring_access_checks (dk_no_check); 7360 /* We must make a copy of ARG, in case subsequent processing 7361 alters any part of it. */ 7362 arg = break_out_target_exprs (arg, /*clear location*/true); 7363 7364 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT, 7365 ICR_DEFAULT_ARGUMENT, fn, parmnum, 7366 complain); 7367 arg = convert_for_arg_passing (type, arg, complain); 7368 pop_deferring_access_checks(); 7369 7370 pop_defarg_context (); 7371 7372 return arg; 7373 } 7374 7375 /* Returns the type which will really be used for passing an argument of 7376 type TYPE. */ 7377 7378 tree 7379 type_passed_as (tree type) 7380 { 7381 /* Pass classes with copy ctors by invisible reference. */ 7382 if (TREE_ADDRESSABLE (type)) 7383 { 7384 type = build_reference_type (type); 7385 /* There are no other pointers to this temporary. */ 7386 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT); 7387 } 7388 else if (targetm.calls.promote_prototypes (NULL_TREE) 7389 && INTEGRAL_TYPE_P (type) 7390 && COMPLETE_TYPE_P (type) 7391 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 7392 type = integer_type_node; 7393 7394 return type; 7395 } 7396 7397 /* Actually perform the appropriate conversion. */ 7398 7399 tree 7400 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain) 7401 { 7402 tree bitfield_type; 7403 7404 /* If VAL is a bitfield, then -- since it has already been converted 7405 to TYPE -- it cannot have a precision greater than TYPE. 7406 7407 If it has a smaller precision, we must widen it here. For 7408 example, passing "int f:3;" to a function expecting an "int" will 7409 not result in any conversion before this point. 7410 7411 If the precision is the same we must not risk widening. For 7412 example, the COMPONENT_REF for a 32-bit "long long" bitfield will 7413 often have type "int", even though the C++ type for the field is 7414 "long long". If the value is being passed to a function 7415 expecting an "int", then no conversions will be required. But, 7416 if we call convert_bitfield_to_declared_type, the bitfield will 7417 be converted to "long long". */ 7418 bitfield_type = is_bitfield_expr_with_lowered_type (val); 7419 if (bitfield_type 7420 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)) 7421 val = convert_to_integer_nofold (TYPE_MAIN_VARIANT (bitfield_type), val); 7422 7423 if (val == error_mark_node) 7424 ; 7425 /* Pass classes with copy ctors by invisible reference. */ 7426 else if (TREE_ADDRESSABLE (type)) 7427 val = build1 (ADDR_EXPR, build_reference_type (type), val); 7428 else if (targetm.calls.promote_prototypes (NULL_TREE) 7429 && INTEGRAL_TYPE_P (type) 7430 && COMPLETE_TYPE_P (type) 7431 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node))) 7432 val = cp_perform_integral_promotions (val, complain); 7433 if (complain & tf_warning) 7434 { 7435 if (warn_suggest_attribute_format) 7436 { 7437 tree rhstype = TREE_TYPE (val); 7438 const enum tree_code coder = TREE_CODE (rhstype); 7439 const enum tree_code codel = TREE_CODE (type); 7440 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) 7441 && coder == codel 7442 && check_missing_format_attribute (type, rhstype)) 7443 warning (OPT_Wsuggest_attribute_format, 7444 "argument of function call might be a candidate " 7445 "for a format attribute"); 7446 } 7447 maybe_warn_parm_abi (type, EXPR_LOC_OR_LOC (val, input_location)); 7448 } 7449 return val; 7450 } 7451 7452 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for 7453 which just decay_conversion or no conversions at all should be done. 7454 This is true for some builtins which don't act like normal functions. 7455 Return 2 if no conversions at all should be done, 1 if just 7456 decay_conversion. Return 3 for special treatment of the 3rd argument 7457 for __builtin_*_overflow_p. */ 7458 7459 int 7460 magic_varargs_p (tree fn) 7461 { 7462 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) 7463 switch (DECL_FUNCTION_CODE (fn)) 7464 { 7465 case BUILT_IN_CLASSIFY_TYPE: 7466 case BUILT_IN_CONSTANT_P: 7467 case BUILT_IN_NEXT_ARG: 7468 case BUILT_IN_VA_START: 7469 return 1; 7470 7471 case BUILT_IN_ADD_OVERFLOW_P: 7472 case BUILT_IN_SUB_OVERFLOW_P: 7473 case BUILT_IN_MUL_OVERFLOW_P: 7474 return 3; 7475 7476 default:; 7477 return lookup_attribute ("type generic", 7478 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0; 7479 } 7480 7481 return 0; 7482 } 7483 7484 /* Returns the decl of the dispatcher function if FN is a function version. */ 7485 7486 tree 7487 get_function_version_dispatcher (tree fn) 7488 { 7489 tree dispatcher_decl = NULL; 7490 7491 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL 7492 && DECL_FUNCTION_VERSIONED (fn)); 7493 7494 gcc_assert (targetm.get_function_versions_dispatcher); 7495 dispatcher_decl = targetm.get_function_versions_dispatcher (fn); 7496 7497 if (dispatcher_decl == NULL) 7498 { 7499 error_at (input_location, "use of multiversioned function " 7500 "without a default"); 7501 return NULL; 7502 } 7503 7504 retrofit_lang_decl (dispatcher_decl); 7505 gcc_assert (dispatcher_decl != NULL); 7506 return dispatcher_decl; 7507 } 7508 7509 /* fn is a function version dispatcher that is marked used. Mark all the 7510 semantically identical function versions it will dispatch as used. */ 7511 7512 void 7513 mark_versions_used (tree fn) 7514 { 7515 struct cgraph_node *node; 7516 struct cgraph_function_version_info *node_v; 7517 struct cgraph_function_version_info *it_v; 7518 7519 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 7520 7521 node = cgraph_node::get (fn); 7522 if (node == NULL) 7523 return; 7524 7525 gcc_assert (node->dispatcher_function); 7526 7527 node_v = node->function_version (); 7528 if (node_v == NULL) 7529 return; 7530 7531 /* All semantically identical versions are chained. Traverse and mark each 7532 one of them as used. */ 7533 it_v = node_v->next; 7534 while (it_v != NULL) 7535 { 7536 mark_used (it_v->this_node->decl); 7537 it_v = it_v->next; 7538 } 7539 } 7540 7541 /* Build a call to "the copy constructor" for the type of A, even if it 7542 wouldn't be selected by normal overload resolution. Used for 7543 diagnostics. */ 7544 7545 static tree 7546 call_copy_ctor (tree a, tsubst_flags_t complain) 7547 { 7548 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a)); 7549 tree binfo = TYPE_BINFO (ctype); 7550 tree copy = get_copy_ctor (ctype, complain); 7551 copy = build_baselink (binfo, binfo, copy, NULL_TREE); 7552 tree ob = build_dummy_object (ctype); 7553 vec<tree, va_gc>* args = make_tree_vector_single (a); 7554 tree r = build_new_method_call (ob, copy, &args, NULL_TREE, 7555 LOOKUP_NORMAL, NULL, complain); 7556 release_tree_vector (args); 7557 return r; 7558 } 7559 7560 /* Return true iff T refers to a base field. */ 7561 7562 static bool 7563 is_base_field_ref (tree t) 7564 { 7565 STRIP_NOPS (t); 7566 if (TREE_CODE (t) == ADDR_EXPR) 7567 t = TREE_OPERAND (t, 0); 7568 if (TREE_CODE (t) == COMPONENT_REF) 7569 t = TREE_OPERAND (t, 1); 7570 if (TREE_CODE (t) == FIELD_DECL) 7571 return DECL_FIELD_IS_BASE (t); 7572 return false; 7573 } 7574 7575 /* We can't elide a copy from a function returning by value to a base 7576 subobject, as the callee might clobber tail padding. Return true iff this 7577 could be that case. */ 7578 7579 static bool 7580 unsafe_copy_elision_p (tree target, tree exp) 7581 { 7582 /* Copy elision only happens with a TARGET_EXPR. */ 7583 if (TREE_CODE (exp) != TARGET_EXPR) 7584 return false; 7585 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); 7586 /* It's safe to elide the copy for a class with no tail padding. */ 7587 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type))) 7588 return false; 7589 /* It's safe to elide the copy if we aren't initializing a base object. */ 7590 if (!is_base_field_ref (target)) 7591 return false; 7592 tree init = TARGET_EXPR_INITIAL (exp); 7593 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */ 7594 while (TREE_CODE (init) == COMPOUND_EXPR) 7595 init = TREE_OPERAND (init, 1); 7596 if (TREE_CODE (init) == COND_EXPR) 7597 { 7598 /* We'll end up copying from each of the arms of the COND_EXPR directly 7599 into the target, so look at them. */ 7600 if (tree op = TREE_OPERAND (init, 1)) 7601 if (unsafe_copy_elision_p (target, op)) 7602 return true; 7603 return unsafe_copy_elision_p (target, TREE_OPERAND (init, 2)); 7604 } 7605 return (TREE_CODE (init) == AGGR_INIT_EXPR 7606 && !AGGR_INIT_VIA_CTOR_P (init)); 7607 } 7608 7609 /* True iff C is a conversion that binds a reference to a prvalue. */ 7610 7611 static bool 7612 conv_binds_ref_to_prvalue (conversion *c) 7613 { 7614 if (c->kind != ck_ref_bind) 7615 return false; 7616 if (c->need_temporary_p) 7617 return true; 7618 7619 c = next_conversion (c); 7620 7621 if (c->kind == ck_rvalue) 7622 return true; 7623 if (c->kind == ck_user && TREE_CODE (c->type) != REFERENCE_TYPE) 7624 return true; 7625 if (c->kind == ck_identity && c->u.expr 7626 && TREE_CODE (c->u.expr) == TARGET_EXPR) 7627 return true; 7628 7629 return false; 7630 } 7631 7632 /* Subroutine of the various build_*_call functions. Overload resolution 7633 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly. 7634 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a 7635 bitmask of various LOOKUP_* flags which apply to the call itself. */ 7636 7637 static tree 7638 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain) 7639 { 7640 tree fn = cand->fn; 7641 const vec<tree, va_gc> *args = cand->args; 7642 tree first_arg = cand->first_arg; 7643 conversion **convs = cand->convs; 7644 conversion *conv; 7645 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn)); 7646 int parmlen; 7647 tree val; 7648 int i = 0; 7649 int j = 0; 7650 unsigned int arg_index = 0; 7651 int is_method = 0; 7652 int nargs; 7653 tree *argarray; 7654 bool already_used = false; 7655 7656 /* In a template, there is no need to perform all of the work that 7657 is normally done. We are only interested in the type of the call 7658 expression, i.e., the return type of the function. Any semantic 7659 errors will be deferred until the template is instantiated. */ 7660 if (processing_template_decl) 7661 { 7662 tree expr, addr; 7663 tree return_type; 7664 const tree *argarray; 7665 unsigned int nargs; 7666 7667 if (undeduced_auto_decl (fn)) 7668 mark_used (fn, complain); 7669 else 7670 /* Otherwise set TREE_USED for the benefit of -Wunused-function. 7671 See PR80598. */ 7672 TREE_USED (fn) = 1; 7673 7674 return_type = TREE_TYPE (TREE_TYPE (fn)); 7675 nargs = vec_safe_length (args); 7676 if (first_arg == NULL_TREE) 7677 argarray = args->address (); 7678 else 7679 { 7680 tree *alcarray; 7681 unsigned int ix; 7682 tree arg; 7683 7684 ++nargs; 7685 alcarray = XALLOCAVEC (tree, nargs); 7686 alcarray[0] = build_this (first_arg); 7687 FOR_EACH_VEC_SAFE_ELT (args, ix, arg) 7688 alcarray[ix + 1] = arg; 7689 argarray = alcarray; 7690 } 7691 7692 addr = build_addr_func (fn, complain); 7693 if (addr == error_mark_node) 7694 return error_mark_node; 7695 expr = build_call_array_loc (input_location, return_type, 7696 addr, nargs, argarray); 7697 if (TREE_THIS_VOLATILE (fn) && cfun) 7698 current_function_returns_abnormally = 1; 7699 return convert_from_reference (expr); 7700 } 7701 7702 /* Give any warnings we noticed during overload resolution. */ 7703 if (cand->warnings && (complain & tf_warning)) 7704 { 7705 struct candidate_warning *w; 7706 for (w = cand->warnings; w; w = w->next) 7707 joust (cand, w->loser, 1, complain); 7708 } 7709 7710 /* Core issue 2327: P0135 doesn't say how to handle the case where the 7711 argument to the copy constructor ends up being a prvalue after 7712 conversion. Let's do the normal processing, but pretend we aren't 7713 actually using the copy constructor. */ 7714 bool force_elide = false; 7715 if (cxx_dialect >= cxx17 7716 && cand->num_convs == 1 7717 && DECL_COMPLETE_CONSTRUCTOR_P (fn) 7718 && (DECL_COPY_CONSTRUCTOR_P (fn) 7719 || DECL_MOVE_CONSTRUCTOR_P (fn)) 7720 && conv_binds_ref_to_prvalue (convs[0])) 7721 { 7722 force_elide = true; 7723 goto not_really_used; 7724 } 7725 7726 /* OK, we're actually calling this inherited constructor; set its deletedness 7727 appropriately. We can get away with doing this here because calling is 7728 the only way to refer to a constructor. */ 7729 if (DECL_INHERITED_CTOR (fn)) 7730 deduce_inheriting_ctor (fn); 7731 7732 /* Make =delete work with SFINAE. */ 7733 if (DECL_DELETED_FN (fn)) 7734 { 7735 if (complain & tf_error) 7736 mark_used (fn); 7737 return error_mark_node; 7738 } 7739 7740 if (DECL_FUNCTION_MEMBER_P (fn)) 7741 { 7742 tree access_fn; 7743 /* If FN is a template function, two cases must be considered. 7744 For example: 7745 7746 struct A { 7747 protected: 7748 template <class T> void f(); 7749 }; 7750 template <class T> struct B { 7751 protected: 7752 void g(); 7753 }; 7754 struct C : A, B<int> { 7755 using A::f; // #1 7756 using B<int>::g; // #2 7757 }; 7758 7759 In case #1 where `A::f' is a member template, DECL_ACCESS is 7760 recorded in the primary template but not in its specialization. 7761 We check access of FN using its primary template. 7762 7763 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply 7764 because it is a member of class template B, DECL_ACCESS is 7765 recorded in the specialization `B<int>::g'. We cannot use its 7766 primary template because `B<T>::g' and `B<int>::g' may have 7767 different access. */ 7768 if (DECL_TEMPLATE_INFO (fn) 7769 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn))) 7770 access_fn = DECL_TI_TEMPLATE (fn); 7771 else 7772 access_fn = fn; 7773 if (!perform_or_defer_access_check (cand->access_path, access_fn, 7774 fn, complain)) 7775 return error_mark_node; 7776 } 7777 7778 /* If we're checking for implicit delete, don't bother with argument 7779 conversions. */ 7780 if (flags & LOOKUP_SPECULATIVE) 7781 { 7782 if (cand->viable == 1) 7783 return fn; 7784 else if (!(complain & tf_error)) 7785 /* Reject bad conversions now. */ 7786 return error_mark_node; 7787 /* else continue to get conversion error. */ 7788 } 7789 7790 not_really_used: 7791 7792 /* N3276 magic doesn't apply to nested calls. */ 7793 tsubst_flags_t decltype_flag = (complain & tf_decltype); 7794 complain &= ~tf_decltype; 7795 /* No-Cleanup doesn't apply to nested calls either. */ 7796 tsubst_flags_t no_cleanup_complain = complain; 7797 complain &= ~tf_no_cleanup; 7798 7799 /* Find maximum size of vector to hold converted arguments. */ 7800 parmlen = list_length (parm); 7801 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0); 7802 if (parmlen > nargs) 7803 nargs = parmlen; 7804 argarray = XALLOCAVEC (tree, nargs); 7805 7806 /* The implicit parameters to a constructor are not considered by overload 7807 resolution, and must be of the proper type. */ 7808 if (DECL_CONSTRUCTOR_P (fn)) 7809 { 7810 tree object_arg; 7811 if (first_arg != NULL_TREE) 7812 { 7813 object_arg = first_arg; 7814 first_arg = NULL_TREE; 7815 } 7816 else 7817 { 7818 object_arg = (*args)[arg_index]; 7819 ++arg_index; 7820 } 7821 argarray[j++] = build_this (object_arg); 7822 parm = TREE_CHAIN (parm); 7823 /* We should never try to call the abstract constructor. */ 7824 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn)); 7825 7826 if (DECL_HAS_VTT_PARM_P (fn)) 7827 { 7828 argarray[j++] = (*args)[arg_index]; 7829 ++arg_index; 7830 parm = TREE_CHAIN (parm); 7831 } 7832 7833 if (flags & LOOKUP_PREFER_RVALUE) 7834 { 7835 /* The implicit move specified in 15.8.3/3 fails "...if the type of 7836 the first parameter of the selected constructor is not an rvalue 7837 reference to the object’s type (possibly cv-qualified)...." */ 7838 gcc_assert (!(complain & tf_error)); 7839 tree ptype = convs[0]->type; 7840 if (TREE_CODE (ptype) != REFERENCE_TYPE 7841 || !TYPE_REF_IS_RVALUE (ptype) 7842 || CONVERSION_RANK (convs[0]) > cr_exact) 7843 return error_mark_node; 7844 } 7845 } 7846 /* Bypass access control for 'this' parameter. */ 7847 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 7848 { 7849 tree parmtype = TREE_VALUE (parm); 7850 tree arg = build_this (first_arg != NULL_TREE 7851 ? first_arg 7852 : (*args)[arg_index]); 7853 tree argtype = TREE_TYPE (arg); 7854 tree converted_arg; 7855 tree base_binfo; 7856 7857 if (arg == error_mark_node) 7858 return error_mark_node; 7859 7860 if (convs[i]->bad_p) 7861 { 7862 if (complain & tf_error) 7863 { 7864 if (permerror (input_location, "passing %qT as %<this%> " 7865 "argument discards qualifiers", 7866 TREE_TYPE (argtype))) 7867 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn); 7868 } 7869 else 7870 return error_mark_node; 7871 } 7872 7873 /* See if the function member or the whole class type is declared 7874 final and the call can be devirtualized. */ 7875 if (DECL_FINAL_P (fn) 7876 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn)))) 7877 flags |= LOOKUP_NONVIRTUAL; 7878 7879 /* [class.mfct.nonstatic]: If a nonstatic member function of a class 7880 X is called for an object that is not of type X, or of a type 7881 derived from X, the behavior is undefined. 7882 7883 So we can assume that anything passed as 'this' is non-null, and 7884 optimize accordingly. */ 7885 gcc_assert (TYPE_PTR_P (parmtype)); 7886 /* Convert to the base in which the function was declared. */ 7887 gcc_assert (cand->conversion_path != NULL_TREE); 7888 converted_arg = build_base_path (PLUS_EXPR, 7889 arg, 7890 cand->conversion_path, 7891 1, complain); 7892 /* Check that the base class is accessible. */ 7893 if (!accessible_base_p (TREE_TYPE (argtype), 7894 BINFO_TYPE (cand->conversion_path), true)) 7895 { 7896 if (complain & tf_error) 7897 error ("%qT is not an accessible base of %qT", 7898 BINFO_TYPE (cand->conversion_path), 7899 TREE_TYPE (argtype)); 7900 else 7901 return error_mark_node; 7902 } 7903 /* If fn was found by a using declaration, the conversion path 7904 will be to the derived class, not the base declaring fn. We 7905 must convert from derived to base. */ 7906 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)), 7907 TREE_TYPE (parmtype), ba_unique, 7908 NULL, complain); 7909 converted_arg = build_base_path (PLUS_EXPR, converted_arg, 7910 base_binfo, 1, complain); 7911 7912 argarray[j++] = converted_arg; 7913 parm = TREE_CHAIN (parm); 7914 if (first_arg != NULL_TREE) 7915 first_arg = NULL_TREE; 7916 else 7917 ++arg_index; 7918 ++i; 7919 is_method = 1; 7920 } 7921 7922 gcc_assert (first_arg == NULL_TREE); 7923 for (; arg_index < vec_safe_length (args) && parm; 7924 parm = TREE_CHAIN (parm), ++arg_index, ++i) 7925 { 7926 tree type = TREE_VALUE (parm); 7927 tree arg = (*args)[arg_index]; 7928 bool conversion_warning = true; 7929 7930 conv = convs[i]; 7931 7932 /* If the argument is NULL and used to (implicitly) instantiate a 7933 template function (and bind one of the template arguments to 7934 the type of 'long int'), we don't want to warn about passing NULL 7935 to non-pointer argument. 7936 For example, if we have this template function: 7937 7938 template<typename T> void func(T x) {} 7939 7940 we want to warn (when -Wconversion is enabled) in this case: 7941 7942 void foo() { 7943 func<int>(NULL); 7944 } 7945 7946 but not in this case: 7947 7948 void foo() { 7949 func(NULL); 7950 } 7951 */ 7952 if (null_node_p (arg) 7953 && DECL_TEMPLATE_INFO (fn) 7954 && cand->template_decl 7955 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS)) 7956 conversion_warning = false; 7957 7958 /* Warn about initializer_list deduction that isn't currently in the 7959 working draft. */ 7960 if (cxx_dialect > cxx98 7961 && flag_deduce_init_list 7962 && cand->template_decl 7963 && is_std_init_list (non_reference (type)) 7964 && BRACE_ENCLOSED_INITIALIZER_P (arg)) 7965 { 7966 tree tmpl = TI_TEMPLATE (cand->template_decl); 7967 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn)); 7968 tree patparm = get_pattern_parm (realparm, tmpl); 7969 tree pattype = TREE_TYPE (patparm); 7970 if (PACK_EXPANSION_P (pattype)) 7971 pattype = PACK_EXPANSION_PATTERN (pattype); 7972 pattype = non_reference (pattype); 7973 7974 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM 7975 && (cand->explicit_targs == NULL_TREE 7976 || (TREE_VEC_LENGTH (cand->explicit_targs) 7977 <= TEMPLATE_TYPE_IDX (pattype)))) 7978 { 7979 pedwarn (input_location, 0, "deducing %qT as %qT", 7980 non_reference (TREE_TYPE (patparm)), 7981 non_reference (type)); 7982 pedwarn (DECL_SOURCE_LOCATION (cand->fn), 0, 7983 " in call to %qD", cand->fn); 7984 pedwarn (input_location, 0, 7985 " (you can disable this with -fno-deduce-init-list)"); 7986 } 7987 } 7988 7989 /* Set user_conv_p on the argument conversions, so rvalue/base handling 7990 knows not to allow any more UDCs. This needs to happen after we 7991 process cand->warnings. */ 7992 if (flags & LOOKUP_NO_CONVERSION) 7993 conv->user_conv_p = true; 7994 7995 tsubst_flags_t arg_complain = complain; 7996 if (!conversion_warning) 7997 arg_complain &= ~tf_warning; 7998 7999 val = convert_like_with_context (conv, arg, fn, i - is_method, 8000 arg_complain); 8001 val = convert_for_arg_passing (type, val, arg_complain); 8002 8003 if (val == error_mark_node) 8004 return error_mark_node; 8005 else 8006 argarray[j++] = val; 8007 } 8008 8009 /* Default arguments */ 8010 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++) 8011 { 8012 if (TREE_VALUE (parm) == error_mark_node) 8013 return error_mark_node; 8014 val = convert_default_arg (TREE_VALUE (parm), 8015 TREE_PURPOSE (parm), 8016 fn, i - is_method, 8017 complain); 8018 if (val == error_mark_node) 8019 return error_mark_node; 8020 argarray[j++] = val; 8021 } 8022 8023 /* Ellipsis */ 8024 int magic = magic_varargs_p (fn); 8025 for (; arg_index < vec_safe_length (args); ++arg_index) 8026 { 8027 tree a = (*args)[arg_index]; 8028 if ((magic == 3 && arg_index == 2) || magic == 2) 8029 { 8030 /* Do no conversions for certain magic varargs. */ 8031 a = mark_type_use (a); 8032 if (TREE_CODE (a) == FUNCTION_DECL && reject_gcc_builtin (a)) 8033 return error_mark_node; 8034 } 8035 else if (magic != 0) 8036 /* For other magic varargs only do decay_conversion. */ 8037 a = decay_conversion (a, complain); 8038 else if (DECL_CONSTRUCTOR_P (fn) 8039 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn), 8040 TREE_TYPE (a))) 8041 { 8042 /* Avoid infinite recursion trying to call A(...). */ 8043 if (complain & tf_error) 8044 /* Try to call the actual copy constructor for a good error. */ 8045 call_copy_ctor (a, complain); 8046 return error_mark_node; 8047 } 8048 else 8049 a = convert_arg_to_ellipsis (a, complain); 8050 if (a == error_mark_node) 8051 return error_mark_node; 8052 argarray[j++] = a; 8053 } 8054 8055 gcc_assert (j <= nargs); 8056 nargs = j; 8057 8058 /* Avoid to do argument-transformation, if warnings for format, and for 8059 nonnull are disabled. Just in case that at least one of them is active 8060 the check_function_arguments function might warn about something. */ 8061 8062 bool warned_p = false; 8063 if (warn_nonnull 8064 || warn_format 8065 || warn_suggest_attribute_format 8066 || warn_restrict) 8067 { 8068 tree *fargs = (!nargs ? argarray 8069 : (tree *) alloca (nargs * sizeof (tree))); 8070 for (j = 0; j < nargs; j++) 8071 { 8072 /* For -Wformat undo the implicit passing by hidden reference 8073 done by convert_arg_to_ellipsis. */ 8074 if (TREE_CODE (argarray[j]) == ADDR_EXPR 8075 && TREE_CODE (TREE_TYPE (argarray[j])) == REFERENCE_TYPE) 8076 fargs[j] = TREE_OPERAND (argarray[j], 0); 8077 else 8078 fargs[j] = maybe_constant_value (argarray[j]); 8079 } 8080 8081 warned_p = check_function_arguments (input_location, fn, TREE_TYPE (fn), 8082 nargs, fargs, NULL); 8083 } 8084 8085 if (DECL_INHERITED_CTOR (fn)) 8086 { 8087 /* Check for passing ellipsis arguments to an inherited constructor. We 8088 could handle this by open-coding the inherited constructor rather than 8089 defining it, but let's not bother now. */ 8090 if (!cp_unevaluated_operand 8091 && cand->num_convs 8092 && cand->convs[cand->num_convs-1]->ellipsis_p) 8093 { 8094 if (complain & tf_error) 8095 { 8096 sorry ("passing arguments to ellipsis of inherited constructor " 8097 "%qD", cand->fn); 8098 inform (DECL_SOURCE_LOCATION (cand->fn), "declared here"); 8099 } 8100 return error_mark_node; 8101 } 8102 8103 /* A base constructor inheriting from a virtual base doesn't get the 8104 inherited arguments, just this and __vtt. */ 8105 if (ctor_omit_inherited_parms (fn)) 8106 nargs = 2; 8107 } 8108 8109 /* Avoid actually calling copy constructors and copy assignment operators, 8110 if possible. */ 8111 8112 if (! flag_elide_constructors && !force_elide) 8113 /* Do things the hard way. */; 8114 else if (cand->num_convs == 1 8115 && (DECL_COPY_CONSTRUCTOR_P (fn) 8116 || DECL_MOVE_CONSTRUCTOR_P (fn)) 8117 /* It's unsafe to elide the constructor when handling 8118 a noexcept-expression, it may evaluate to the wrong 8119 value (c++/53025). */ 8120 && (force_elide || cp_noexcept_operand == 0)) 8121 { 8122 tree targ; 8123 tree arg = argarray[num_artificial_parms_for (fn)]; 8124 tree fa; 8125 bool trivial = trivial_fn_p (fn); 8126 8127 /* Pull out the real argument, disregarding const-correctness. */ 8128 targ = arg; 8129 /* Strip the reference binding for the constructor parameter. */ 8130 if (CONVERT_EXPR_P (targ) 8131 && TREE_CODE (TREE_TYPE (targ)) == REFERENCE_TYPE) 8132 targ = TREE_OPERAND (targ, 0); 8133 /* But don't strip any other reference bindings; binding a temporary to a 8134 reference prevents copy elision. */ 8135 while ((CONVERT_EXPR_P (targ) 8136 && TREE_CODE (TREE_TYPE (targ)) != REFERENCE_TYPE) 8137 || TREE_CODE (targ) == NON_LVALUE_EXPR) 8138 targ = TREE_OPERAND (targ, 0); 8139 if (TREE_CODE (targ) == ADDR_EXPR) 8140 { 8141 targ = TREE_OPERAND (targ, 0); 8142 if (!same_type_ignoring_top_level_qualifiers_p 8143 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ))) 8144 targ = NULL_TREE; 8145 } 8146 else 8147 targ = NULL_TREE; 8148 8149 if (targ) 8150 arg = targ; 8151 else 8152 arg = cp_build_fold_indirect_ref (arg); 8153 8154 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base 8155 subobject. */ 8156 if (CHECKING_P && cxx_dialect >= cxx17) 8157 gcc_assert (TREE_CODE (arg) != TARGET_EXPR 8158 || force_elide 8159 /* It's from binding the ref parm to a packed field. */ 8160 || convs[0]->need_temporary_p 8161 || seen_error () 8162 /* See unsafe_copy_elision_p. */ 8163 || DECL_BASE_CONSTRUCTOR_P (fn)); 8164 8165 /* [class.copy]: the copy constructor is implicitly defined even if 8166 the implementation elided its use. */ 8167 if (!trivial && !force_elide) 8168 { 8169 if (!mark_used (fn, complain) && !(complain & tf_error)) 8170 return error_mark_node; 8171 already_used = true; 8172 } 8173 8174 /* If we're creating a temp and we already have one, don't create a 8175 new one. If we're not creating a temp but we get one, use 8176 INIT_EXPR to collapse the temp into our target. Otherwise, if the 8177 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a 8178 temp or an INIT_EXPR otherwise. */ 8179 fa = argarray[0]; 8180 if (is_dummy_object (fa)) 8181 { 8182 if (TREE_CODE (arg) == TARGET_EXPR) 8183 return arg; 8184 else if (trivial) 8185 return force_target_expr (DECL_CONTEXT (fn), arg, complain); 8186 } 8187 else if ((trivial || TREE_CODE (arg) == TARGET_EXPR) 8188 && !unsafe_copy_elision_p (fa, arg)) 8189 { 8190 tree to = cp_stabilize_reference (cp_build_fold_indirect_ref (fa)); 8191 8192 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg); 8193 return val; 8194 } 8195 } 8196 else if (DECL_ASSIGNMENT_OPERATOR_P (fn) 8197 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR) 8198 && trivial_fn_p (fn)) 8199 { 8200 tree to = cp_stabilize_reference 8201 (cp_build_fold_indirect_ref (argarray[0])); 8202 tree type = TREE_TYPE (to); 8203 tree as_base = CLASSTYPE_AS_BASE (type); 8204 tree arg = argarray[1]; 8205 8206 if (is_really_empty_class (type)) 8207 { 8208 /* Avoid copying empty classes. */ 8209 val = build2 (COMPOUND_EXPR, type, arg, to); 8210 TREE_NO_WARNING (val) = 1; 8211 } 8212 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base))) 8213 { 8214 arg = cp_build_fold_indirect_ref (arg); 8215 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg); 8216 } 8217 else 8218 { 8219 /* We must only copy the non-tail padding parts. */ 8220 tree arg0, arg2, t; 8221 tree array_type, alias_set; 8222 8223 arg2 = TYPE_SIZE_UNIT (as_base); 8224 arg0 = cp_build_addr_expr (to, complain); 8225 8226 array_type = build_array_type (unsigned_char_type_node, 8227 build_index_type 8228 (size_binop (MINUS_EXPR, 8229 arg2, size_int (1)))); 8230 alias_set = build_int_cst (build_pointer_type (type), 0); 8231 t = build2 (MODIFY_EXPR, void_type_node, 8232 build2 (MEM_REF, array_type, arg0, alias_set), 8233 build2 (MEM_REF, array_type, arg, alias_set)); 8234 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to); 8235 TREE_NO_WARNING (val) = 1; 8236 } 8237 8238 return val; 8239 } 8240 else if (trivial_fn_p (fn)) 8241 { 8242 if (DECL_DESTRUCTOR_P (fn)) 8243 return fold_convert (void_type_node, argarray[0]); 8244 else if (default_ctor_p (fn)) 8245 { 8246 if (is_dummy_object (argarray[0])) 8247 return force_target_expr (DECL_CONTEXT (fn), void_node, 8248 no_cleanup_complain); 8249 else 8250 return cp_build_fold_indirect_ref (argarray[0]); 8251 } 8252 } 8253 8254 gcc_assert (!force_elide); 8255 8256 if (!already_used 8257 && !mark_used (fn, complain)) 8258 return error_mark_node; 8259 8260 /* Warn if the built-in writes to an object of a non-trivial type. */ 8261 if (warn_class_memaccess 8262 && vec_safe_length (args) >= 2 8263 && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL) 8264 maybe_warn_class_memaccess (input_location, fn, args); 8265 8266 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0 8267 /* Don't mess with virtual lookup in instantiate_non_dependent_expr; 8268 virtual functions can't be constexpr. */ 8269 && !in_template_function ()) 8270 { 8271 tree t; 8272 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])), 8273 DECL_CONTEXT (fn), 8274 ba_any, NULL, complain); 8275 gcc_assert (binfo && binfo != error_mark_node); 8276 8277 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1, 8278 complain); 8279 if (TREE_SIDE_EFFECTS (argarray[0])) 8280 argarray[0] = save_expr (argarray[0]); 8281 t = build_pointer_type (TREE_TYPE (fn)); 8282 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn)); 8283 TREE_TYPE (fn) = t; 8284 } 8285 else 8286 { 8287 fn = build_addr_func (fn, complain); 8288 if (fn == error_mark_node) 8289 return error_mark_node; 8290 } 8291 8292 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag); 8293 if (call == error_mark_node) 8294 return call; 8295 if (cand->flags & LOOKUP_LIST_INIT_CTOR) 8296 { 8297 tree c = extract_call_expr (call); 8298 /* build_new_op_1 will clear this when appropriate. */ 8299 CALL_EXPR_ORDERED_ARGS (c) = true; 8300 } 8301 if (warned_p) 8302 { 8303 tree c = extract_call_expr (call); 8304 if (TREE_CODE (c) == CALL_EXPR) 8305 TREE_NO_WARNING (c) = 1; 8306 } 8307 return call; 8308 } 8309 8310 namespace 8311 { 8312 8313 /* Return the DECL of the first non-static subobject of class TYPE 8314 that satisfies the predicate PRED or null if none can be found. */ 8315 8316 template <class Predicate> 8317 tree 8318 first_non_static_field (tree type, Predicate pred) 8319 { 8320 if (!type || !CLASS_TYPE_P (type)) 8321 return NULL_TREE; 8322 8323 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field)) 8324 { 8325 if (TREE_CODE (field) != FIELD_DECL) 8326 continue; 8327 if (TREE_STATIC (field)) 8328 continue; 8329 if (pred (field)) 8330 return field; 8331 } 8332 8333 int i = 0; 8334 8335 for (tree base_binfo, binfo = TYPE_BINFO (type); 8336 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 8337 { 8338 tree base = TREE_TYPE (base_binfo); 8339 if (pred (base)) 8340 return base; 8341 if (tree field = first_non_static_field (base, pred)) 8342 return field; 8343 } 8344 8345 return NULL_TREE; 8346 } 8347 8348 struct NonPublicField 8349 { 8350 bool operator() (const_tree t) 8351 { 8352 return DECL_P (t) && (TREE_PRIVATE (t) || TREE_PROTECTED (t)); 8353 } 8354 }; 8355 8356 /* Return the DECL of the first non-public subobject of class TYPE 8357 or null if none can be found. */ 8358 8359 static inline tree 8360 first_non_public_field (tree type) 8361 { 8362 return first_non_static_field (type, NonPublicField ()); 8363 } 8364 8365 struct NonTrivialField 8366 { 8367 bool operator() (const_tree t) 8368 { 8369 return !trivial_type_p (DECL_P (t) ? TREE_TYPE (t) : t); 8370 } 8371 }; 8372 8373 /* Return the DECL of the first non-trivial subobject of class TYPE 8374 or null if none can be found. */ 8375 8376 static inline tree 8377 first_non_trivial_field (tree type) 8378 { 8379 return first_non_static_field (type, NonTrivialField ()); 8380 } 8381 8382 } /* unnamed namespace */ 8383 8384 /* Return true if all copy and move assignment operator overloads for 8385 class TYPE are trivial and at least one of them is not deleted and, 8386 when ACCESS is set, accessible. Return false otherwise. Set 8387 HASASSIGN to true when the TYPE has a (not necessarily trivial) 8388 copy or move assignment. */ 8389 8390 static bool 8391 has_trivial_copy_assign_p (tree type, bool access, bool *hasassign) 8392 { 8393 tree fns = get_class_binding (type, assign_op_identifier); 8394 bool all_trivial = true; 8395 8396 /* Iterate over overloads of the assignment operator, checking 8397 accessible copy assignments for triviality. */ 8398 8399 for (ovl_iterator oi (fns); oi; ++oi) 8400 { 8401 tree f = *oi; 8402 8403 /* Skip operators that aren't copy assignments. */ 8404 if (!copy_fn_p (f)) 8405 continue; 8406 8407 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f)) 8408 || accessible_p (TYPE_BINFO (type), f, true)); 8409 8410 /* Skip template assignment operators and deleted functions. */ 8411 if (TREE_CODE (f) != FUNCTION_DECL || DECL_DELETED_FN (f)) 8412 continue; 8413 8414 if (accessible) 8415 *hasassign = true; 8416 8417 if (!accessible || !trivial_fn_p (f)) 8418 all_trivial = false; 8419 8420 /* Break early when both properties have been determined. */ 8421 if (*hasassign && !all_trivial) 8422 break; 8423 } 8424 8425 /* Return true if they're all trivial and one of the expressions 8426 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */ 8427 tree ref = cp_build_reference_type (type, false); 8428 return (all_trivial 8429 && (is_trivially_xible (MODIFY_EXPR, type, type) 8430 || is_trivially_xible (MODIFY_EXPR, type, ref))); 8431 } 8432 8433 /* Return true if all copy and move ctor overloads for class TYPE are 8434 trivial and at least one of them is not deleted and, when ACCESS is 8435 set, accessible. Return false otherwise. Set each element of HASCTOR[] 8436 to true when the TYPE has a (not necessarily trivial) default and copy 8437 (or move) ctor, respectively. */ 8438 8439 static bool 8440 has_trivial_copy_p (tree type, bool access, bool hasctor[2]) 8441 { 8442 tree fns = get_class_binding (type, complete_ctor_identifier); 8443 bool all_trivial = true; 8444 8445 for (ovl_iterator oi (fns); oi; ++oi) 8446 { 8447 tree f = *oi; 8448 8449 /* Skip template constructors. */ 8450 if (TREE_CODE (f) != FUNCTION_DECL) 8451 continue; 8452 8453 bool cpy_or_move_ctor_p = copy_fn_p (f); 8454 8455 /* Skip ctors other than default, copy, and move. */ 8456 if (!cpy_or_move_ctor_p && !default_ctor_p (f)) 8457 continue; 8458 8459 if (DECL_DELETED_FN (f)) 8460 continue; 8461 8462 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f)) 8463 || accessible_p (TYPE_BINFO (type), f, true)); 8464 8465 if (accessible) 8466 hasctor[cpy_or_move_ctor_p] = true; 8467 8468 if (cpy_or_move_ctor_p && (!accessible || !trivial_fn_p (f))) 8469 all_trivial = false; 8470 8471 /* Break early when both properties have been determined. */ 8472 if (hasctor[0] && hasctor[1] && !all_trivial) 8473 break; 8474 } 8475 8476 return all_trivial; 8477 } 8478 8479 /* Issue a warning on a call to the built-in function FNDECL if it is 8480 a raw memory write whose destination is not an object of (something 8481 like) trivial or standard layout type with a non-deleted assignment 8482 and copy ctor. Detects const correctness violations, corrupting 8483 references, virtual table pointers, and bypassing non-trivial 8484 assignments. */ 8485 8486 static void 8487 maybe_warn_class_memaccess (location_t loc, tree fndecl, 8488 const vec<tree, va_gc> *args) 8489 { 8490 /* Except for bcopy where it's second, the destination pointer is 8491 the first argument for all functions handled here. Compute 8492 the index of the destination and source arguments. */ 8493 unsigned dstidx = DECL_FUNCTION_CODE (fndecl) == BUILT_IN_BCOPY; 8494 unsigned srcidx = !dstidx; 8495 8496 tree dest = (*args)[dstidx]; 8497 if (!TREE_TYPE (dest) || !POINTER_TYPE_P (TREE_TYPE (dest))) 8498 return; 8499 8500 tree srctype = NULL_TREE; 8501 8502 /* Determine the type of the pointed-to object and whether it's 8503 a complete class type. */ 8504 tree desttype = TREE_TYPE (TREE_TYPE (dest)); 8505 8506 if (!desttype || !COMPLETE_TYPE_P (desttype) || !CLASS_TYPE_P (desttype)) 8507 return; 8508 8509 /* Check to see if the raw memory call is made by a non-static member 8510 function with THIS as the destination argument for the destination 8511 type. If so, and if the class has no non-trivial bases or members, 8512 be more permissive. */ 8513 if (current_function_decl 8514 && DECL_NONSTATIC_MEMBER_FUNCTION_P (current_function_decl) 8515 && is_this_parameter (tree_strip_nop_conversions (dest))) 8516 { 8517 tree ctx = DECL_CONTEXT (current_function_decl); 8518 bool special = same_type_ignoring_top_level_qualifiers_p (ctx, desttype); 8519 tree binfo = TYPE_BINFO (ctx); 8520 8521 /* FIXME: The following if statement is overly permissive (see 8522 bug 84851). Remove it in GCC 9. */ 8523 if (special 8524 && !BINFO_VTABLE (binfo) 8525 && !BINFO_N_BASE_BINFOS (binfo) 8526 && (DECL_CONSTRUCTOR_P (current_function_decl) 8527 || DECL_DESTRUCTOR_P (current_function_decl))) 8528 return; 8529 8530 if (special 8531 && !BINFO_VTABLE (binfo) 8532 && !first_non_trivial_field (desttype)) 8533 return; 8534 } 8535 8536 /* True if the class is trivial. */ 8537 bool trivial = trivial_type_p (desttype); 8538 8539 /* Set to true if DESTYPE has an accessible copy assignment. */ 8540 bool hasassign = false; 8541 /* True if all of the class' overloaded copy assignment operators 8542 are all trivial (and not deleted) and at least one of them is 8543 accessible. */ 8544 bool trivassign = has_trivial_copy_assign_p (desttype, true, &hasassign); 8545 8546 /* Set to true if DESTTYPE has an accessible default and copy ctor, 8547 respectively. */ 8548 bool hasctors[2] = { false, false }; 8549 8550 /* True if all of the class' overloaded copy constructors are all 8551 trivial (and not deleted) and at least one of them is accessible. */ 8552 bool trivcopy = has_trivial_copy_p (desttype, true, hasctors); 8553 8554 /* Set FLD to the first private/protected member of the class. */ 8555 tree fld = trivial ? first_non_public_field (desttype) : NULL_TREE; 8556 8557 /* The warning format string. */ 8558 const char *warnfmt = NULL; 8559 /* A suggested alternative to offer instead of the raw memory call. 8560 Empty string when none can be come up with. */ 8561 const char *suggest = ""; 8562 bool warned = false; 8563 8564 switch (DECL_FUNCTION_CODE (fndecl)) 8565 { 8566 case BUILT_IN_MEMSET: 8567 if (!integer_zerop (maybe_constant_value ((*args)[1]))) 8568 { 8569 /* Diagnose setting non-copy-assignable or non-trivial types, 8570 or types with a private member, to (potentially) non-zero 8571 bytes. Since the value of the bytes being written is unknown, 8572 suggest using assignment instead (if one exists). Also warn 8573 for writes into objects for which zero-initialization doesn't 8574 mean all bits clear (pointer-to-member data, where null is all 8575 bits set). Since the value being written is (most likely) 8576 non-zero, simply suggest assignment (but not copy assignment). */ 8577 suggest = "; use assignment instead"; 8578 if (!trivassign) 8579 warnfmt = G_("%qD writing to an object of type %#qT with " 8580 "no trivial copy-assignment"); 8581 else if (!trivial) 8582 warnfmt = G_("%qD writing to an object of non-trivial type %#qT%s"); 8583 else if (fld) 8584 { 8585 const char *access = TREE_PRIVATE (fld) ? "private" : "protected"; 8586 warned = warning_at (loc, OPT_Wclass_memaccess, 8587 "%qD writing to an object of type %#qT with " 8588 "%qs member %qD", 8589 fndecl, desttype, access, fld); 8590 } 8591 else if (!zero_init_p (desttype)) 8592 warnfmt = G_("%qD writing to an object of type %#qT containing " 8593 "a pointer to data member%s"); 8594 8595 break; 8596 } 8597 /* Fall through. */ 8598 8599 case BUILT_IN_BZERO: 8600 /* Similarly to the above, diagnose clearing non-trivial or non- 8601 standard layout objects, or objects of types with no assignmenmt. 8602 Since the value being written is known to be zero, suggest either 8603 copy assignment, copy ctor, or default ctor as an alternative, 8604 depending on what's available. */ 8605 8606 if (hasassign && hasctors[0]) 8607 suggest = G_("; use assignment or value-initialization instead"); 8608 else if (hasassign) 8609 suggest = G_("; use assignment instead"); 8610 else if (hasctors[0]) 8611 suggest = G_("; use value-initialization instead"); 8612 8613 if (!trivassign) 8614 warnfmt = G_("%qD clearing an object of type %#qT with " 8615 "no trivial copy-assignment%s"); 8616 else if (!trivial) 8617 warnfmt = G_("%qD clearing an object of non-trivial type %#qT%s"); 8618 else if (!zero_init_p (desttype)) 8619 warnfmt = G_("%qD clearing an object of type %#qT containing " 8620 "a pointer-to-member%s"); 8621 break; 8622 8623 case BUILT_IN_BCOPY: 8624 case BUILT_IN_MEMCPY: 8625 case BUILT_IN_MEMMOVE: 8626 case BUILT_IN_MEMPCPY: 8627 /* Determine the type of the source object. */ 8628 srctype = TREE_TYPE ((*args)[srcidx]); 8629 if (!srctype || !POINTER_TYPE_P (srctype)) 8630 srctype = void_type_node; 8631 else 8632 srctype = TREE_TYPE (srctype); 8633 8634 /* Since it's impossible to determine wheter the byte copy is 8635 being used in place of assignment to an existing object or 8636 as a substitute for initialization, assume it's the former. 8637 Determine the best alternative to use instead depending on 8638 what's not deleted. */ 8639 if (hasassign && hasctors[1]) 8640 suggest = G_("; use copy-assignment or copy-initialization instead"); 8641 else if (hasassign) 8642 suggest = G_("; use copy-assignment instead"); 8643 else if (hasctors[1]) 8644 suggest = G_("; use copy-initialization instead"); 8645 8646 if (!trivassign) 8647 warnfmt = G_("%qD writing to an object of type %#qT with no trivial " 8648 "copy-assignment%s"); 8649 else if (!trivially_copyable_p (desttype)) 8650 warnfmt = G_("%qD writing to an object of non-trivially copyable " 8651 "type %#qT%s"); 8652 else if (!trivcopy) 8653 warnfmt = G_("%qD writing to an object with a deleted copy constructor"); 8654 8655 else if (!trivial 8656 && !VOID_TYPE_P (srctype) 8657 && !char_type_p (TYPE_MAIN_VARIANT (srctype)) 8658 && !same_type_ignoring_top_level_qualifiers_p (desttype, 8659 srctype)) 8660 { 8661 /* Warn when copying into a non-trivial object from an object 8662 of a different type other than void or char. */ 8663 warned = warning_at (loc, OPT_Wclass_memaccess, 8664 "%qD copying an object of non-trivial type " 8665 "%#qT from an array of %#qT", 8666 fndecl, desttype, srctype); 8667 } 8668 else if (fld 8669 && !VOID_TYPE_P (srctype) 8670 && !char_type_p (TYPE_MAIN_VARIANT (srctype)) 8671 && !same_type_ignoring_top_level_qualifiers_p (desttype, 8672 srctype)) 8673 { 8674 const char *access = TREE_PRIVATE (fld) ? "private" : "protected"; 8675 warned = warning_at (loc, OPT_Wclass_memaccess, 8676 "%qD copying an object of type %#qT with " 8677 "%qs member %qD from an array of %#qT; use " 8678 "assignment or copy-initialization instead", 8679 fndecl, desttype, access, fld, srctype); 8680 } 8681 else if (!trivial && vec_safe_length (args) > 2) 8682 { 8683 tree sz = maybe_constant_value ((*args)[2]); 8684 if (!tree_fits_uhwi_p (sz)) 8685 break; 8686 8687 /* Finally, warn on partial copies. */ 8688 unsigned HOST_WIDE_INT typesize 8689 = tree_to_uhwi (TYPE_SIZE_UNIT (desttype)); 8690 if (unsigned HOST_WIDE_INT partial = tree_to_uhwi (sz) % typesize) 8691 warned = warning_at (loc, OPT_Wclass_memaccess, 8692 (typesize - partial > 1 8693 ? G_("%qD writing to an object of " 8694 "a non-trivial type %#qT leaves %wu " 8695 "bytes unchanged") 8696 : G_("%qD writing to an object of " 8697 "a non-trivial type %#qT leaves %wu " 8698 "byte unchanged")), 8699 fndecl, desttype, typesize - partial); 8700 } 8701 break; 8702 8703 case BUILT_IN_REALLOC: 8704 8705 if (!trivially_copyable_p (desttype)) 8706 warnfmt = G_("%qD moving an object of non-trivially copyable type " 8707 "%#qT; use %<new%> and %<delete%> instead"); 8708 else if (!trivcopy) 8709 warnfmt = G_("%qD moving an object of type %#qT with deleted copy " 8710 "constructor; use %<new%> and %<delete%> instead"); 8711 else if (!get_dtor (desttype, tf_none)) 8712 warnfmt = G_("%qD moving an object of type %#qT with deleted " 8713 "destructor"); 8714 else if (!trivial) 8715 { 8716 tree sz = maybe_constant_value ((*args)[1]); 8717 if (TREE_CODE (sz) == INTEGER_CST 8718 && tree_int_cst_lt (sz, TYPE_SIZE_UNIT (desttype))) 8719 /* Finally, warn on reallocation into insufficient space. */ 8720 warned = warning_at (loc, OPT_Wclass_memaccess, 8721 "%qD moving an object of non-trivial type " 8722 "%#qT and size %E into a region of size %E", 8723 fndecl, desttype, TYPE_SIZE_UNIT (desttype), 8724 sz); 8725 } 8726 break; 8727 8728 default: 8729 return; 8730 } 8731 8732 if (warnfmt) 8733 { 8734 if (suggest) 8735 warned = warning_at (loc, OPT_Wclass_memaccess, 8736 warnfmt, fndecl, desttype, suggest); 8737 else 8738 warned = warning_at (loc, OPT_Wclass_memaccess, 8739 warnfmt, fndecl, desttype); 8740 } 8741 8742 if (warned) 8743 inform (location_of (desttype), "%#qT declared here", desttype); 8744 } 8745 8746 /* Build and return a call to FN, using NARGS arguments in ARGARRAY. 8747 This function performs no overload resolution, conversion, or other 8748 high-level operations. */ 8749 8750 tree 8751 build_cxx_call (tree fn, int nargs, tree *argarray, 8752 tsubst_flags_t complain) 8753 { 8754 tree fndecl; 8755 8756 /* Remember roughly where this call is. */ 8757 location_t loc = EXPR_LOC_OR_LOC (fn, input_location); 8758 fn = build_call_a (fn, nargs, argarray); 8759 SET_EXPR_LOCATION (fn, loc); 8760 8761 fndecl = get_callee_fndecl (fn); 8762 8763 /* Check that arguments to builtin functions match the expectations. */ 8764 if (fndecl 8765 && DECL_BUILT_IN (fndecl) 8766 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) 8767 { 8768 int i; 8769 8770 /* We need to take care that values to BUILT_IN_NORMAL 8771 are reduced. */ 8772 for (i = 0; i < nargs; i++) 8773 argarray[i] = fold_non_dependent_expr (argarray[i]); 8774 8775 if (!check_builtin_function_arguments (EXPR_LOCATION (fn), vNULL, fndecl, 8776 nargs, argarray)) 8777 return error_mark_node; 8778 } 8779 8780 if (VOID_TYPE_P (TREE_TYPE (fn))) 8781 return fn; 8782 8783 /* 5.2.2/11: If a function call is a prvalue of object type: if the 8784 function call is either the operand of a decltype-specifier or the 8785 right operand of a comma operator that is the operand of a 8786 decltype-specifier, a temporary object is not introduced for the 8787 prvalue. The type of the prvalue may be incomplete. */ 8788 if (!(complain & tf_decltype)) 8789 { 8790 fn = require_complete_type_sfinae (fn, complain); 8791 if (fn == error_mark_node) 8792 return error_mark_node; 8793 8794 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn))) 8795 { 8796 fn = build_cplus_new (TREE_TYPE (fn), fn, complain); 8797 maybe_warn_parm_abi (TREE_TYPE (fn), loc); 8798 } 8799 } 8800 return convert_from_reference (fn); 8801 } 8802 8803 /* Returns the value to use for the in-charge parameter when making a 8804 call to a function with the indicated NAME. 8805 8806 FIXME:Can't we find a neater way to do this mapping? */ 8807 8808 tree 8809 in_charge_arg_for_name (tree name) 8810 { 8811 if (IDENTIFIER_CTOR_P (name)) 8812 { 8813 if (name == complete_ctor_identifier) 8814 return integer_one_node; 8815 gcc_checking_assert (name == base_ctor_identifier); 8816 } 8817 else 8818 { 8819 if (name == complete_dtor_identifier) 8820 return integer_two_node; 8821 else if (name == deleting_dtor_identifier) 8822 return integer_three_node; 8823 gcc_checking_assert (name == base_dtor_identifier); 8824 } 8825 8826 return integer_zero_node; 8827 } 8828 8829 /* We've built up a constructor call RET. Complain if it delegates to the 8830 constructor we're currently compiling. */ 8831 8832 static void 8833 check_self_delegation (tree ret) 8834 { 8835 if (TREE_CODE (ret) == TARGET_EXPR) 8836 ret = TARGET_EXPR_INITIAL (ret); 8837 tree fn = cp_get_callee_fndecl_nofold (ret); 8838 if (fn && DECL_ABSTRACT_ORIGIN (fn) == current_function_decl) 8839 error ("constructor delegates to itself"); 8840 } 8841 8842 /* Build a call to a constructor, destructor, or an assignment 8843 operator for INSTANCE, an expression with class type. NAME 8844 indicates the special member function to call; *ARGS are the 8845 arguments. ARGS may be NULL. This may change ARGS. BINFO 8846 indicates the base of INSTANCE that is to be passed as the `this' 8847 parameter to the member function called. 8848 8849 FLAGS are the LOOKUP_* flags to use when processing the call. 8850 8851 If NAME indicates a complete object constructor, INSTANCE may be 8852 NULL_TREE. In this case, the caller will call build_cplus_new to 8853 store the newly constructed object into a VAR_DECL. */ 8854 8855 tree 8856 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args, 8857 tree binfo, int flags, tsubst_flags_t complain) 8858 { 8859 tree fns; 8860 /* The type of the subobject to be constructed or destroyed. */ 8861 tree class_type; 8862 vec<tree, va_gc> *allocated = NULL; 8863 tree ret; 8864 8865 gcc_assert (IDENTIFIER_CDTOR_P (name) || name == assign_op_identifier); 8866 if (TYPE_P (binfo)) 8867 { 8868 /* Resolve the name. */ 8869 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain)) 8870 return error_mark_node; 8871 8872 binfo = TYPE_BINFO (binfo); 8873 } 8874 8875 gcc_assert (binfo != NULL_TREE); 8876 8877 class_type = BINFO_TYPE (binfo); 8878 8879 /* Handle the special case where INSTANCE is NULL_TREE. */ 8880 if (name == complete_ctor_identifier && !instance) 8881 instance = build_dummy_object (class_type); 8882 else 8883 { 8884 if (IDENTIFIER_DTOR_P (name)) 8885 gcc_assert (args == NULL || vec_safe_is_empty (*args)); 8886 8887 /* Convert to the base class, if necessary. */ 8888 if (!same_type_ignoring_top_level_qualifiers_p 8889 (TREE_TYPE (instance), BINFO_TYPE (binfo))) 8890 { 8891 if (IDENTIFIER_CDTOR_P (name)) 8892 /* For constructors and destructors, either the base is 8893 non-virtual, or it is virtual but we are doing the 8894 conversion from a constructor or destructor for the 8895 complete object. In either case, we can convert 8896 statically. */ 8897 instance = convert_to_base_statically (instance, binfo); 8898 else 8899 { 8900 /* However, for assignment operators, we must convert 8901 dynamically if the base is virtual. */ 8902 gcc_checking_assert (name == assign_op_identifier); 8903 instance = build_base_path (PLUS_EXPR, instance, 8904 binfo, /*nonnull=*/1, complain); 8905 } 8906 } 8907 } 8908 8909 gcc_assert (instance != NULL_TREE); 8910 8911 /* In C++17, "If the initializer expression is a prvalue and the 8912 cv-unqualified version of the source type is the same class as the class 8913 of the destination, the initializer expression is used to initialize the 8914 destination object." Handle that here to avoid doing overload 8915 resolution. */ 8916 if (cxx_dialect >= cxx17 8917 && args && vec_safe_length (*args) == 1 8918 && name == complete_ctor_identifier) 8919 { 8920 tree arg = (**args)[0]; 8921 8922 if (BRACE_ENCLOSED_INITIALIZER_P (arg) 8923 && !TYPE_HAS_LIST_CTOR (class_type) 8924 && CONSTRUCTOR_NELTS (arg) == 1) 8925 arg = CONSTRUCTOR_ELT (arg, 0)->value; 8926 8927 if ((TREE_CODE (arg) == TARGET_EXPR 8928 || TREE_CODE (arg) == CONSTRUCTOR) 8929 && (same_type_ignoring_top_level_qualifiers_p 8930 (class_type, TREE_TYPE (arg)))) 8931 { 8932 if (is_dummy_object (instance)) 8933 return arg; 8934 else if (TREE_CODE (arg) == TARGET_EXPR) 8935 TARGET_EXPR_DIRECT_INIT_P (arg) = true; 8936 8937 if ((complain & tf_error) 8938 && (flags & LOOKUP_DELEGATING_CONS)) 8939 check_self_delegation (arg); 8940 /* Avoid change of behavior on Wunused-var-2.C. */ 8941 instance = mark_lvalue_use (instance); 8942 return build2 (INIT_EXPR, class_type, instance, arg); 8943 } 8944 } 8945 8946 fns = lookup_fnfields (binfo, name, 1); 8947 8948 /* When making a call to a constructor or destructor for a subobject 8949 that uses virtual base classes, pass down a pointer to a VTT for 8950 the subobject. */ 8951 if ((name == base_ctor_identifier 8952 || name == base_dtor_identifier) 8953 && CLASSTYPE_VBASECLASSES (class_type)) 8954 { 8955 tree vtt; 8956 tree sub_vtt; 8957 8958 /* If the current function is a complete object constructor 8959 or destructor, then we fetch the VTT directly. 8960 Otherwise, we look it up using the VTT we were given. */ 8961 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type)); 8962 vtt = decay_conversion (vtt, complain); 8963 if (vtt == error_mark_node) 8964 return error_mark_node; 8965 vtt = build_if_in_charge (vtt, current_vtt_parm); 8966 if (BINFO_SUBVTT_INDEX (binfo)) 8967 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo)); 8968 else 8969 sub_vtt = vtt; 8970 8971 if (args == NULL) 8972 { 8973 allocated = make_tree_vector (); 8974 args = &allocated; 8975 } 8976 8977 vec_safe_insert (*args, 0, sub_vtt); 8978 } 8979 8980 ret = build_new_method_call (instance, fns, args, 8981 TYPE_BINFO (BINFO_TYPE (binfo)), 8982 flags, /*fn=*/NULL, 8983 complain); 8984 8985 if (allocated != NULL) 8986 release_tree_vector (allocated); 8987 8988 if ((complain & tf_error) 8989 && (flags & LOOKUP_DELEGATING_CONS) 8990 && name == complete_ctor_identifier) 8991 check_self_delegation (ret); 8992 8993 return ret; 8994 } 8995 8996 /* Return the NAME, as a C string. The NAME indicates a function that 8997 is a member of TYPE. *FREE_P is set to true if the caller must 8998 free the memory returned. 8999 9000 Rather than go through all of this, we should simply set the names 9001 of constructors and destructors appropriately, and dispense with 9002 ctor_identifier, dtor_identifier, etc. */ 9003 9004 static char * 9005 name_as_c_string (tree name, tree type, bool *free_p) 9006 { 9007 const char *pretty_name; 9008 9009 /* Assume that we will not allocate memory. */ 9010 *free_p = false; 9011 /* Constructors and destructors are special. */ 9012 if (IDENTIFIER_CDTOR_P (name)) 9013 { 9014 pretty_name 9015 = identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))); 9016 /* For a destructor, add the '~'. */ 9017 if (IDENTIFIER_DTOR_P (name)) 9018 { 9019 pretty_name = concat ("~", pretty_name, NULL); 9020 /* Remember that we need to free the memory allocated. */ 9021 *free_p = true; 9022 } 9023 } 9024 else if (IDENTIFIER_CONV_OP_P (name)) 9025 { 9026 pretty_name = concat ("operator ", 9027 type_as_string_translate (TREE_TYPE (name), 9028 TFF_PLAIN_IDENTIFIER), 9029 NULL); 9030 /* Remember that we need to free the memory allocated. */ 9031 *free_p = true; 9032 } 9033 else 9034 pretty_name = identifier_to_locale (IDENTIFIER_POINTER (name)); 9035 9036 return CONST_CAST (char *, pretty_name); 9037 } 9038 9039 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will 9040 be set, upon return, to the function called. ARGS may be NULL. 9041 This may change ARGS. */ 9042 9043 static tree 9044 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args, 9045 tree conversion_path, int flags, 9046 tree *fn_p, tsubst_flags_t complain) 9047 { 9048 struct z_candidate *candidates = 0, *cand; 9049 tree explicit_targs = NULL_TREE; 9050 tree basetype = NULL_TREE; 9051 tree access_binfo, binfo; 9052 tree optype; 9053 tree first_mem_arg = NULL_TREE; 9054 tree name; 9055 bool skip_first_for_error; 9056 vec<tree, va_gc> *user_args; 9057 tree call; 9058 tree fn; 9059 int template_only = 0; 9060 bool any_viable_p; 9061 tree orig_instance; 9062 tree orig_fns; 9063 vec<tree, va_gc> *orig_args = NULL; 9064 void *p; 9065 9066 gcc_assert (instance != NULL_TREE); 9067 9068 /* We don't know what function we're going to call, yet. */ 9069 if (fn_p) 9070 *fn_p = NULL_TREE; 9071 9072 if (error_operand_p (instance) 9073 || !fns || error_operand_p (fns)) 9074 return error_mark_node; 9075 9076 if (!BASELINK_P (fns)) 9077 { 9078 if (complain & tf_error) 9079 error ("call to non-function %qD", fns); 9080 return error_mark_node; 9081 } 9082 9083 orig_instance = instance; 9084 orig_fns = fns; 9085 9086 /* Dismantle the baselink to collect all the information we need. */ 9087 if (!conversion_path) 9088 conversion_path = BASELINK_BINFO (fns); 9089 access_binfo = BASELINK_ACCESS_BINFO (fns); 9090 binfo = BASELINK_BINFO (fns); 9091 optype = BASELINK_OPTYPE (fns); 9092 fns = BASELINK_FUNCTIONS (fns); 9093 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR) 9094 { 9095 explicit_targs = TREE_OPERAND (fns, 1); 9096 fns = TREE_OPERAND (fns, 0); 9097 template_only = 1; 9098 } 9099 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL 9100 || TREE_CODE (fns) == TEMPLATE_DECL 9101 || TREE_CODE (fns) == OVERLOAD); 9102 fn = OVL_FIRST (fns); 9103 name = DECL_NAME (fn); 9104 9105 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance)); 9106 gcc_assert (CLASS_TYPE_P (basetype)); 9107 9108 user_args = args == NULL ? NULL : *args; 9109 /* Under DR 147 A::A() is an invalid constructor call, 9110 not a functional cast. */ 9111 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 9112 { 9113 if (! (complain & tf_error)) 9114 return error_mark_node; 9115 9116 basetype = DECL_CONTEXT (fn); 9117 name = constructor_name (basetype); 9118 if (permerror (input_location, 9119 "cannot call constructor %<%T::%D%> directly", 9120 basetype, name)) 9121 inform (input_location, "for a function-style cast, remove the " 9122 "redundant %<::%D%>", name); 9123 call = build_functional_cast (basetype, build_tree_list_vec (user_args), 9124 complain); 9125 return call; 9126 } 9127 9128 if (processing_template_decl) 9129 { 9130 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args); 9131 instance = build_non_dependent_expr (instance); 9132 if (args != NULL) 9133 make_args_non_dependent (*args); 9134 } 9135 9136 /* Process the argument list. */ 9137 if (args != NULL && *args != NULL) 9138 { 9139 *args = resolve_args (*args, complain); 9140 if (*args == NULL) 9141 return error_mark_node; 9142 user_args = *args; 9143 } 9144 9145 /* Consider the object argument to be used even if we end up selecting a 9146 static member function. */ 9147 instance = mark_type_use (instance); 9148 9149 /* Figure out whether to skip the first argument for the error 9150 message we will display to users if an error occurs. We don't 9151 want to display any compiler-generated arguments. The "this" 9152 pointer hasn't been added yet. However, we must remove the VTT 9153 pointer if this is a call to a base-class constructor or 9154 destructor. */ 9155 skip_first_for_error = false; 9156 if (IDENTIFIER_CDTOR_P (name)) 9157 { 9158 /* Callers should explicitly indicate whether they want to ctor 9159 the complete object or just the part without virtual bases. */ 9160 gcc_assert (name != ctor_identifier); 9161 9162 /* Remove the VTT pointer, if present. */ 9163 if ((name == base_ctor_identifier || name == base_dtor_identifier) 9164 && CLASSTYPE_VBASECLASSES (basetype)) 9165 skip_first_for_error = true; 9166 9167 /* It's OK to call destructors and constructors on cv-qualified 9168 objects. Therefore, convert the INSTANCE to the unqualified 9169 type, if necessary. */ 9170 if (!same_type_p (basetype, TREE_TYPE (instance))) 9171 { 9172 instance = build_this (instance); 9173 instance = build_nop (build_pointer_type (basetype), instance); 9174 instance = build_fold_indirect_ref (instance); 9175 } 9176 } 9177 else 9178 gcc_assert (!DECL_DESTRUCTOR_P (fn) && !DECL_CONSTRUCTOR_P (fn)); 9179 9180 /* For the overload resolution we need to find the actual `this` 9181 that would be captured if the call turns out to be to a 9182 non-static member function. Do not actually capture it at this 9183 point. */ 9184 if (DECL_CONSTRUCTOR_P (fn)) 9185 /* Constructors don't use the enclosing 'this'. */ 9186 first_mem_arg = instance; 9187 else 9188 first_mem_arg = maybe_resolve_dummy (instance, false); 9189 9190 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 9191 p = conversion_obstack_alloc (0); 9192 9193 /* The number of arguments artificial parms in ARGS; we subtract one because 9194 there's no 'this' in ARGS. */ 9195 unsigned skip = num_artificial_parms_for (fn) - 1; 9196 9197 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form 9198 initializer, not T({ }). */ 9199 if (DECL_CONSTRUCTOR_P (fn) 9200 && vec_safe_length (user_args) > skip 9201 && DIRECT_LIST_INIT_P ((*user_args)[skip])) 9202 { 9203 tree init_list = (*user_args)[skip]; 9204 tree init = NULL_TREE; 9205 9206 gcc_assert (user_args->length () == skip + 1 9207 && !(flags & LOOKUP_ONLYCONVERTING)); 9208 9209 /* If the initializer list has no elements and T is a class type with 9210 a default constructor, the object is value-initialized. Handle 9211 this here so we don't need to handle it wherever we use 9212 build_special_member_call. */ 9213 if (CONSTRUCTOR_NELTS (init_list) == 0 9214 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype) 9215 /* For a user-provided default constructor, use the normal 9216 mechanisms so that protected access works. */ 9217 && type_has_non_user_provided_default_constructor (basetype) 9218 && !processing_template_decl) 9219 init = build_value_init (basetype, complain); 9220 9221 /* If BASETYPE is an aggregate, we need to do aggregate 9222 initialization. */ 9223 else if (CP_AGGREGATE_TYPE_P (basetype)) 9224 { 9225 init = reshape_init (basetype, init_list, complain); 9226 init = digest_init (basetype, init, complain); 9227 } 9228 9229 if (init) 9230 { 9231 if (is_dummy_object (instance)) 9232 return get_target_expr_sfinae (init, complain); 9233 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init); 9234 TREE_SIDE_EFFECTS (init) = true; 9235 return init; 9236 } 9237 9238 /* Otherwise go ahead with overload resolution. */ 9239 add_list_candidates (fns, first_mem_arg, user_args, 9240 basetype, explicit_targs, template_only, 9241 conversion_path, access_binfo, flags, 9242 &candidates, complain); 9243 } 9244 else 9245 add_candidates (fns, first_mem_arg, user_args, optype, 9246 explicit_targs, template_only, conversion_path, 9247 access_binfo, flags, &candidates, complain); 9248 9249 any_viable_p = false; 9250 candidates = splice_viable (candidates, false, &any_viable_p); 9251 9252 if (!any_viable_p) 9253 { 9254 if (complain & tf_error) 9255 { 9256 if (!COMPLETE_OR_OPEN_TYPE_P (basetype)) 9257 cxx_incomplete_type_error (instance, basetype); 9258 else if (optype) 9259 error ("no matching function for call to %<%T::operator %T(%A)%#V%>", 9260 basetype, optype, build_tree_list_vec (user_args), 9261 TREE_TYPE (instance)); 9262 else 9263 { 9264 tree arglist = build_tree_list_vec (user_args); 9265 tree errname = name; 9266 bool twiddle = false; 9267 if (IDENTIFIER_CDTOR_P (errname)) 9268 { 9269 twiddle = IDENTIFIER_DTOR_P (errname); 9270 errname = constructor_name (basetype); 9271 } 9272 if (explicit_targs) 9273 errname = lookup_template_function (errname, explicit_targs); 9274 if (skip_first_for_error) 9275 arglist = TREE_CHAIN (arglist); 9276 error ("no matching function for call to %<%T::%s%E(%A)%#V%>", 9277 basetype, &"~"[!twiddle], errname, arglist, 9278 TREE_TYPE (instance)); 9279 } 9280 print_z_candidates (location_of (name), candidates); 9281 } 9282 call = error_mark_node; 9283 } 9284 else 9285 { 9286 cand = tourney (candidates, complain); 9287 if (cand == 0) 9288 { 9289 char *pretty_name; 9290 bool free_p; 9291 tree arglist; 9292 9293 if (complain & tf_error) 9294 { 9295 pretty_name = name_as_c_string (name, basetype, &free_p); 9296 arglist = build_tree_list_vec (user_args); 9297 if (skip_first_for_error) 9298 arglist = TREE_CHAIN (arglist); 9299 if (!any_strictly_viable (candidates)) 9300 error ("no matching function for call to %<%s(%A)%>", 9301 pretty_name, arglist); 9302 else 9303 error ("call of overloaded %<%s(%A)%> is ambiguous", 9304 pretty_name, arglist); 9305 print_z_candidates (location_of (name), candidates); 9306 if (free_p) 9307 free (pretty_name); 9308 } 9309 call = error_mark_node; 9310 } 9311 else 9312 { 9313 fn = cand->fn; 9314 call = NULL_TREE; 9315 9316 if (!(flags & LOOKUP_NONVIRTUAL) 9317 && DECL_PURE_VIRTUAL_P (fn) 9318 && instance == current_class_ref 9319 && (complain & tf_warning)) 9320 { 9321 /* This is not an error, it is runtime undefined 9322 behavior. */ 9323 if (!current_function_decl) 9324 warning (0, "pure virtual %q#D called from " 9325 "non-static data member initializer", fn); 9326 else if (DECL_CONSTRUCTOR_P (current_function_decl) 9327 || DECL_DESTRUCTOR_P (current_function_decl)) 9328 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) 9329 ? G_("pure virtual %q#D called from constructor") 9330 : G_("pure virtual %q#D called from destructor")), 9331 fn); 9332 } 9333 9334 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE 9335 && !DECL_CONSTRUCTOR_P (fn) 9336 && is_dummy_object (instance)) 9337 { 9338 instance = maybe_resolve_dummy (instance, true); 9339 if (instance == error_mark_node) 9340 call = error_mark_node; 9341 else if (!is_dummy_object (instance)) 9342 { 9343 /* We captured 'this' in the current lambda now that 9344 we know we really need it. */ 9345 cand->first_arg = instance; 9346 } 9347 else if (any_dependent_bases_p ()) 9348 /* We can't tell until instantiation time whether we can use 9349 *this as the implicit object argument. */; 9350 else 9351 { 9352 if (complain & tf_error) 9353 error ("cannot call member function %qD without object", 9354 fn); 9355 call = error_mark_node; 9356 } 9357 } 9358 9359 if (call != error_mark_node) 9360 { 9361 /* Optimize away vtable lookup if we know that this 9362 function can't be overridden. We need to check if 9363 the context and the type where we found fn are the same, 9364 actually FN might be defined in a different class 9365 type because of a using-declaration. In this case, we 9366 do not want to perform a non-virtual call. */ 9367 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL) 9368 && same_type_ignoring_top_level_qualifiers_p 9369 (DECL_CONTEXT (fn), BINFO_TYPE (binfo)) 9370 && resolves_to_fixed_type_p (instance, 0)) 9371 flags |= LOOKUP_NONVIRTUAL; 9372 if (explicit_targs) 9373 flags |= LOOKUP_EXPLICIT_TMPL_ARGS; 9374 /* Now we know what function is being called. */ 9375 if (fn_p) 9376 *fn_p = fn; 9377 /* Build the actual CALL_EXPR. */ 9378 call = build_over_call (cand, flags, complain); 9379 /* In an expression of the form `a->f()' where `f' turns 9380 out to be a static member function, `a' is 9381 none-the-less evaluated. */ 9382 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE 9383 && !is_dummy_object (instance) 9384 && TREE_SIDE_EFFECTS (instance)) 9385 { 9386 /* But avoid the implicit lvalue-rvalue conversion when 'a' 9387 is volatile. */ 9388 tree a = instance; 9389 if (TREE_THIS_VOLATILE (a)) 9390 a = build_this (a); 9391 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), a, call); 9392 } 9393 else if (call != error_mark_node 9394 && DECL_DESTRUCTOR_P (cand->fn) 9395 && !VOID_TYPE_P (TREE_TYPE (call))) 9396 /* An explicit call of the form "x->~X()" has type 9397 "void". However, on platforms where destructors 9398 return "this" (i.e., those where 9399 targetm.cxx.cdtor_returns_this is true), such calls 9400 will appear to have a return value of pointer type 9401 to the low-level call machinery. We do not want to 9402 change the low-level machinery, since we want to be 9403 able to optimize "delete f()" on such platforms as 9404 "operator delete(~X(f()))" (rather than generating 9405 "t = f(), ~X(t), operator delete (t)"). */ 9406 call = build_nop (void_type_node, call); 9407 } 9408 } 9409 } 9410 9411 if (processing_template_decl && call != error_mark_node) 9412 { 9413 bool cast_to_void = false; 9414 9415 if (TREE_CODE (call) == COMPOUND_EXPR) 9416 call = TREE_OPERAND (call, 1); 9417 else if (TREE_CODE (call) == NOP_EXPR) 9418 { 9419 cast_to_void = true; 9420 call = TREE_OPERAND (call, 0); 9421 } 9422 if (INDIRECT_REF_P (call)) 9423 call = TREE_OPERAND (call, 0); 9424 call = (build_min_non_dep_call_vec 9425 (call, 9426 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)), 9427 orig_instance, orig_fns, NULL_TREE), 9428 orig_args)); 9429 SET_EXPR_LOCATION (call, input_location); 9430 call = convert_from_reference (call); 9431 if (cast_to_void) 9432 call = build_nop (void_type_node, call); 9433 } 9434 9435 /* Free all the conversions we allocated. */ 9436 obstack_free (&conversion_obstack, p); 9437 9438 if (orig_args != NULL) 9439 release_tree_vector (orig_args); 9440 9441 return call; 9442 } 9443 9444 /* Wrapper for above. */ 9445 9446 tree 9447 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args, 9448 tree conversion_path, int flags, 9449 tree *fn_p, tsubst_flags_t complain) 9450 { 9451 tree ret; 9452 bool subtime = timevar_cond_start (TV_OVERLOAD); 9453 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags, 9454 fn_p, complain); 9455 timevar_cond_stop (TV_OVERLOAD, subtime); 9456 return ret; 9457 } 9458 9459 /* Returns true iff standard conversion sequence ICS1 is a proper 9460 subsequence of ICS2. */ 9461 9462 static bool 9463 is_subseq (conversion *ics1, conversion *ics2) 9464 { 9465 /* We can assume that a conversion of the same code 9466 between the same types indicates a subsequence since we only get 9467 here if the types we are converting from are the same. */ 9468 9469 while (ics1->kind == ck_rvalue 9470 || ics1->kind == ck_lvalue) 9471 ics1 = next_conversion (ics1); 9472 9473 while (1) 9474 { 9475 while (ics2->kind == ck_rvalue 9476 || ics2->kind == ck_lvalue) 9477 ics2 = next_conversion (ics2); 9478 9479 if (ics2->kind == ck_user 9480 || ics2->kind == ck_ambig 9481 || ics2->kind == ck_aggr 9482 || ics2->kind == ck_list 9483 || ics2->kind == ck_identity) 9484 /* At this point, ICS1 cannot be a proper subsequence of 9485 ICS2. We can get a USER_CONV when we are comparing the 9486 second standard conversion sequence of two user conversion 9487 sequences. */ 9488 return false; 9489 9490 ics2 = next_conversion (ics2); 9491 9492 while (ics2->kind == ck_rvalue 9493 || ics2->kind == ck_lvalue) 9494 ics2 = next_conversion (ics2); 9495 9496 if (ics2->kind == ics1->kind 9497 && same_type_p (ics2->type, ics1->type) 9498 && (ics1->kind == ck_identity 9499 || same_type_p (next_conversion (ics2)->type, 9500 next_conversion (ics1)->type))) 9501 return true; 9502 } 9503 } 9504 9505 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may 9506 be any _TYPE nodes. */ 9507 9508 bool 9509 is_properly_derived_from (tree derived, tree base) 9510 { 9511 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base)) 9512 return false; 9513 9514 /* We only allow proper derivation here. The DERIVED_FROM_P macro 9515 considers every class derived from itself. */ 9516 return (!same_type_ignoring_top_level_qualifiers_p (derived, base) 9517 && DERIVED_FROM_P (base, derived)); 9518 } 9519 9520 /* We build the ICS for an implicit object parameter as a pointer 9521 conversion sequence. However, such a sequence should be compared 9522 as if it were a reference conversion sequence. If ICS is the 9523 implicit conversion sequence for an implicit object parameter, 9524 modify it accordingly. */ 9525 9526 static void 9527 maybe_handle_implicit_object (conversion **ics) 9528 { 9529 if ((*ics)->this_p) 9530 { 9531 /* [over.match.funcs] 9532 9533 For non-static member functions, the type of the 9534 implicit object parameter is "reference to cv X" 9535 where X is the class of which the function is a 9536 member and cv is the cv-qualification on the member 9537 function declaration. */ 9538 conversion *t = *ics; 9539 tree reference_type; 9540 9541 /* The `this' parameter is a pointer to a class type. Make the 9542 implicit conversion talk about a reference to that same class 9543 type. */ 9544 reference_type = TREE_TYPE (t->type); 9545 reference_type = build_reference_type (reference_type); 9546 9547 if (t->kind == ck_qual) 9548 t = next_conversion (t); 9549 if (t->kind == ck_ptr) 9550 t = next_conversion (t); 9551 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE); 9552 t = direct_reference_binding (reference_type, t); 9553 t->this_p = 1; 9554 t->rvaluedness_matches_p = 0; 9555 *ics = t; 9556 } 9557 } 9558 9559 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion, 9560 and return the initial reference binding conversion. Otherwise, 9561 leave *ICS unchanged and return NULL. */ 9562 9563 static conversion * 9564 maybe_handle_ref_bind (conversion **ics) 9565 { 9566 if ((*ics)->kind == ck_ref_bind) 9567 { 9568 conversion *old_ics = *ics; 9569 *ics = next_conversion (old_ics); 9570 (*ics)->user_conv_p = old_ics->user_conv_p; 9571 return old_ics; 9572 } 9573 9574 return NULL; 9575 } 9576 9577 /* Compare two implicit conversion sequences according to the rules set out in 9578 [over.ics.rank]. Return values: 9579 9580 1: ics1 is better than ics2 9581 -1: ics2 is better than ics1 9582 0: ics1 and ics2 are indistinguishable */ 9583 9584 static int 9585 compare_ics (conversion *ics1, conversion *ics2) 9586 { 9587 tree from_type1; 9588 tree from_type2; 9589 tree to_type1; 9590 tree to_type2; 9591 tree deref_from_type1 = NULL_TREE; 9592 tree deref_from_type2 = NULL_TREE; 9593 tree deref_to_type1 = NULL_TREE; 9594 tree deref_to_type2 = NULL_TREE; 9595 conversion_rank rank1, rank2; 9596 9597 /* REF_BINDING is nonzero if the result of the conversion sequence 9598 is a reference type. In that case REF_CONV is the reference 9599 binding conversion. */ 9600 conversion *ref_conv1; 9601 conversion *ref_conv2; 9602 9603 /* Compare badness before stripping the reference conversion. */ 9604 if (ics1->bad_p > ics2->bad_p) 9605 return -1; 9606 else if (ics1->bad_p < ics2->bad_p) 9607 return 1; 9608 9609 /* Handle implicit object parameters. */ 9610 maybe_handle_implicit_object (&ics1); 9611 maybe_handle_implicit_object (&ics2); 9612 9613 /* Handle reference parameters. */ 9614 ref_conv1 = maybe_handle_ref_bind (&ics1); 9615 ref_conv2 = maybe_handle_ref_bind (&ics2); 9616 9617 /* List-initialization sequence L1 is a better conversion sequence than 9618 list-initialization sequence L2 if L1 converts to 9619 std::initializer_list<X> for some X and L2 does not. */ 9620 if (ics1->kind == ck_list && ics2->kind != ck_list) 9621 return 1; 9622 if (ics2->kind == ck_list && ics1->kind != ck_list) 9623 return -1; 9624 9625 /* [over.ics.rank] 9626 9627 When comparing the basic forms of implicit conversion sequences (as 9628 defined in _over.best.ics_) 9629 9630 --a standard conversion sequence (_over.ics.scs_) is a better 9631 conversion sequence than a user-defined conversion sequence 9632 or an ellipsis conversion sequence, and 9633 9634 --a user-defined conversion sequence (_over.ics.user_) is a 9635 better conversion sequence than an ellipsis conversion sequence 9636 (_over.ics.ellipsis_). */ 9637 /* Use BAD_CONVERSION_RANK because we already checked for a badness 9638 mismatch. If both ICS are bad, we try to make a decision based on 9639 what would have happened if they'd been good. This is not an 9640 extension, we'll still give an error when we build up the call; this 9641 just helps us give a more helpful error message. */ 9642 rank1 = BAD_CONVERSION_RANK (ics1); 9643 rank2 = BAD_CONVERSION_RANK (ics2); 9644 9645 if (rank1 > rank2) 9646 return -1; 9647 else if (rank1 < rank2) 9648 return 1; 9649 9650 if (ics1->ellipsis_p) 9651 /* Both conversions are ellipsis conversions. */ 9652 return 0; 9653 9654 /* User-defined conversion sequence U1 is a better conversion sequence 9655 than another user-defined conversion sequence U2 if they contain the 9656 same user-defined conversion operator or constructor and if the sec- 9657 ond standard conversion sequence of U1 is better than the second 9658 standard conversion sequence of U2. */ 9659 9660 /* Handle list-conversion with the same code even though it isn't always 9661 ranked as a user-defined conversion and it doesn't have a second 9662 standard conversion sequence; it will still have the desired effect. 9663 Specifically, we need to do the reference binding comparison at the 9664 end of this function. */ 9665 9666 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr) 9667 { 9668 conversion *t1; 9669 conversion *t2; 9670 9671 for (t1 = ics1; t1->kind != ck_user; t1 = next_conversion (t1)) 9672 if (t1->kind == ck_ambig || t1->kind == ck_aggr 9673 || t1->kind == ck_list) 9674 break; 9675 for (t2 = ics2; t2->kind != ck_user; t2 = next_conversion (t2)) 9676 if (t2->kind == ck_ambig || t2->kind == ck_aggr 9677 || t2->kind == ck_list) 9678 break; 9679 9680 if (t1->kind != t2->kind) 9681 return 0; 9682 else if (t1->kind == ck_user) 9683 { 9684 tree f1 = t1->cand ? t1->cand->fn : t1->type; 9685 tree f2 = t2->cand ? t2->cand->fn : t2->type; 9686 if (f1 != f2) 9687 return 0; 9688 } 9689 else 9690 { 9691 /* For ambiguous or aggregate conversions, use the target type as 9692 a proxy for the conversion function. */ 9693 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type)) 9694 return 0; 9695 } 9696 9697 /* We can just fall through here, after setting up 9698 FROM_TYPE1 and FROM_TYPE2. */ 9699 from_type1 = t1->type; 9700 from_type2 = t2->type; 9701 } 9702 else 9703 { 9704 conversion *t1; 9705 conversion *t2; 9706 9707 /* We're dealing with two standard conversion sequences. 9708 9709 [over.ics.rank] 9710 9711 Standard conversion sequence S1 is a better conversion 9712 sequence than standard conversion sequence S2 if 9713 9714 --S1 is a proper subsequence of S2 (comparing the conversion 9715 sequences in the canonical form defined by _over.ics.scs_, 9716 excluding any Lvalue Transformation; the identity 9717 conversion sequence is considered to be a subsequence of 9718 any non-identity conversion sequence */ 9719 9720 t1 = ics1; 9721 while (t1->kind != ck_identity) 9722 t1 = next_conversion (t1); 9723 from_type1 = t1->type; 9724 9725 t2 = ics2; 9726 while (t2->kind != ck_identity) 9727 t2 = next_conversion (t2); 9728 from_type2 = t2->type; 9729 } 9730 9731 /* One sequence can only be a subsequence of the other if they start with 9732 the same type. They can start with different types when comparing the 9733 second standard conversion sequence in two user-defined conversion 9734 sequences. */ 9735 if (same_type_p (from_type1, from_type2)) 9736 { 9737 if (is_subseq (ics1, ics2)) 9738 return 1; 9739 if (is_subseq (ics2, ics1)) 9740 return -1; 9741 } 9742 9743 /* [over.ics.rank] 9744 9745 Or, if not that, 9746 9747 --the rank of S1 is better than the rank of S2 (by the rules 9748 defined below): 9749 9750 Standard conversion sequences are ordered by their ranks: an Exact 9751 Match is a better conversion than a Promotion, which is a better 9752 conversion than a Conversion. 9753 9754 Two conversion sequences with the same rank are indistinguishable 9755 unless one of the following rules applies: 9756 9757 --A conversion that does not a convert a pointer, pointer to member, 9758 or std::nullptr_t to bool is better than one that does. 9759 9760 The ICS_STD_RANK automatically handles the pointer-to-bool rule, 9761 so that we do not have to check it explicitly. */ 9762 if (ics1->rank < ics2->rank) 9763 return 1; 9764 else if (ics2->rank < ics1->rank) 9765 return -1; 9766 9767 to_type1 = ics1->type; 9768 to_type2 = ics2->type; 9769 9770 /* A conversion from scalar arithmetic type to complex is worse than a 9771 conversion between scalar arithmetic types. */ 9772 if (same_type_p (from_type1, from_type2) 9773 && ARITHMETIC_TYPE_P (from_type1) 9774 && ARITHMETIC_TYPE_P (to_type1) 9775 && ARITHMETIC_TYPE_P (to_type2) 9776 && ((TREE_CODE (to_type1) == COMPLEX_TYPE) 9777 != (TREE_CODE (to_type2) == COMPLEX_TYPE))) 9778 { 9779 if (TREE_CODE (to_type1) == COMPLEX_TYPE) 9780 return -1; 9781 else 9782 return 1; 9783 } 9784 9785 if (TYPE_PTR_P (from_type1) 9786 && TYPE_PTR_P (from_type2) 9787 && TYPE_PTR_P (to_type1) 9788 && TYPE_PTR_P (to_type2)) 9789 { 9790 deref_from_type1 = TREE_TYPE (from_type1); 9791 deref_from_type2 = TREE_TYPE (from_type2); 9792 deref_to_type1 = TREE_TYPE (to_type1); 9793 deref_to_type2 = TREE_TYPE (to_type2); 9794 } 9795 /* The rules for pointers to members A::* are just like the rules 9796 for pointers A*, except opposite: if B is derived from A then 9797 A::* converts to B::*, not vice versa. For that reason, we 9798 switch the from_ and to_ variables here. */ 9799 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2) 9800 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2)) 9801 || (TYPE_PTRMEMFUNC_P (from_type1) 9802 && TYPE_PTRMEMFUNC_P (from_type2) 9803 && TYPE_PTRMEMFUNC_P (to_type1) 9804 && TYPE_PTRMEMFUNC_P (to_type2))) 9805 { 9806 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1); 9807 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2); 9808 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1); 9809 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2); 9810 } 9811 9812 if (deref_from_type1 != NULL_TREE 9813 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1)) 9814 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2))) 9815 { 9816 /* This was one of the pointer or pointer-like conversions. 9817 9818 [over.ics.rank] 9819 9820 --If class B is derived directly or indirectly from class A, 9821 conversion of B* to A* is better than conversion of B* to 9822 void*, and conversion of A* to void* is better than 9823 conversion of B* to void*. */ 9824 if (VOID_TYPE_P (deref_to_type1) 9825 && VOID_TYPE_P (deref_to_type2)) 9826 { 9827 if (is_properly_derived_from (deref_from_type1, 9828 deref_from_type2)) 9829 return -1; 9830 else if (is_properly_derived_from (deref_from_type2, 9831 deref_from_type1)) 9832 return 1; 9833 } 9834 else if (VOID_TYPE_P (deref_to_type1) 9835 || VOID_TYPE_P (deref_to_type2)) 9836 { 9837 if (same_type_p (deref_from_type1, deref_from_type2)) 9838 { 9839 if (VOID_TYPE_P (deref_to_type2)) 9840 { 9841 if (is_properly_derived_from (deref_from_type1, 9842 deref_to_type1)) 9843 return 1; 9844 } 9845 /* We know that DEREF_TO_TYPE1 is `void' here. */ 9846 else if (is_properly_derived_from (deref_from_type1, 9847 deref_to_type2)) 9848 return -1; 9849 } 9850 } 9851 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1)) 9852 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2))) 9853 { 9854 /* [over.ics.rank] 9855 9856 --If class B is derived directly or indirectly from class A 9857 and class C is derived directly or indirectly from B, 9858 9859 --conversion of C* to B* is better than conversion of C* to 9860 A*, 9861 9862 --conversion of B* to A* is better than conversion of C* to 9863 A* */ 9864 if (same_type_p (deref_from_type1, deref_from_type2)) 9865 { 9866 if (is_properly_derived_from (deref_to_type1, 9867 deref_to_type2)) 9868 return 1; 9869 else if (is_properly_derived_from (deref_to_type2, 9870 deref_to_type1)) 9871 return -1; 9872 } 9873 else if (same_type_p (deref_to_type1, deref_to_type2)) 9874 { 9875 if (is_properly_derived_from (deref_from_type2, 9876 deref_from_type1)) 9877 return 1; 9878 else if (is_properly_derived_from (deref_from_type1, 9879 deref_from_type2)) 9880 return -1; 9881 } 9882 } 9883 } 9884 else if (CLASS_TYPE_P (non_reference (from_type1)) 9885 && same_type_p (from_type1, from_type2)) 9886 { 9887 tree from = non_reference (from_type1); 9888 9889 /* [over.ics.rank] 9890 9891 --binding of an expression of type C to a reference of type 9892 B& is better than binding an expression of type C to a 9893 reference of type A& 9894 9895 --conversion of C to B is better than conversion of C to A, */ 9896 if (is_properly_derived_from (from, to_type1) 9897 && is_properly_derived_from (from, to_type2)) 9898 { 9899 if (is_properly_derived_from (to_type1, to_type2)) 9900 return 1; 9901 else if (is_properly_derived_from (to_type2, to_type1)) 9902 return -1; 9903 } 9904 } 9905 else if (CLASS_TYPE_P (non_reference (to_type1)) 9906 && same_type_p (to_type1, to_type2)) 9907 { 9908 tree to = non_reference (to_type1); 9909 9910 /* [over.ics.rank] 9911 9912 --binding of an expression of type B to a reference of type 9913 A& is better than binding an expression of type C to a 9914 reference of type A&, 9915 9916 --conversion of B to A is better than conversion of C to A */ 9917 if (is_properly_derived_from (from_type1, to) 9918 && is_properly_derived_from (from_type2, to)) 9919 { 9920 if (is_properly_derived_from (from_type2, from_type1)) 9921 return 1; 9922 else if (is_properly_derived_from (from_type1, from_type2)) 9923 return -1; 9924 } 9925 } 9926 9927 /* [over.ics.rank] 9928 9929 --S1 and S2 differ only in their qualification conversion and yield 9930 similar types T1 and T2 (_conv.qual_), respectively, and the cv- 9931 qualification signature of type T1 is a proper subset of the cv- 9932 qualification signature of type T2 */ 9933 if (ics1->kind == ck_qual 9934 && ics2->kind == ck_qual 9935 && same_type_p (from_type1, from_type2)) 9936 { 9937 int result = comp_cv_qual_signature (to_type1, to_type2); 9938 if (result != 0) 9939 return result; 9940 } 9941 9942 /* [over.ics.rank] 9943 9944 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers 9945 to an implicit object parameter of a non-static member function 9946 declared without a ref-qualifier, and either S1 binds an lvalue 9947 reference to an lvalue and S2 binds an rvalue reference or S1 binds an 9948 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x 9949 draft standard, 13.3.3.2) 9950 9951 --S1 and S2 are reference bindings (_dcl.init.ref_), and the 9952 types to which the references refer are the same type except for 9953 top-level cv-qualifiers, and the type to which the reference 9954 initialized by S2 refers is more cv-qualified than the type to 9955 which the reference initialized by S1 refers. 9956 9957 DR 1328 [over.match.best]: the context is an initialization by 9958 conversion function for direct reference binding (13.3.1.6) of a 9959 reference to function type, the return type of F1 is the same kind of 9960 reference (i.e. lvalue or rvalue) as the reference being initialized, 9961 and the return type of F2 is not. */ 9962 9963 if (ref_conv1 && ref_conv2) 9964 { 9965 if (!ref_conv1->this_p && !ref_conv2->this_p 9966 && (ref_conv1->rvaluedness_matches_p 9967 != ref_conv2->rvaluedness_matches_p) 9968 && (same_type_p (ref_conv1->type, ref_conv2->type) 9969 || (TYPE_REF_IS_RVALUE (ref_conv1->type) 9970 != TYPE_REF_IS_RVALUE (ref_conv2->type)))) 9971 { 9972 if (ref_conv1->bad_p 9973 && !same_type_p (TREE_TYPE (ref_conv1->type), 9974 TREE_TYPE (ref_conv2->type))) 9975 /* Don't prefer a bad conversion that drops cv-quals to a bad 9976 conversion with the wrong rvalueness. */ 9977 return 0; 9978 return (ref_conv1->rvaluedness_matches_p 9979 - ref_conv2->rvaluedness_matches_p); 9980 } 9981 9982 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2)) 9983 { 9984 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type)); 9985 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type)); 9986 if (ref_conv1->bad_p) 9987 { 9988 /* Prefer the one that drops fewer cv-quals. */ 9989 tree ftype = next_conversion (ref_conv1)->type; 9990 int fquals = cp_type_quals (ftype); 9991 q1 ^= fquals; 9992 q2 ^= fquals; 9993 } 9994 return comp_cv_qualification (q2, q1); 9995 } 9996 } 9997 9998 /* Neither conversion sequence is better than the other. */ 9999 return 0; 10000 } 10001 10002 /* The source type for this standard conversion sequence. */ 10003 10004 static tree 10005 source_type (conversion *t) 10006 { 10007 for (;; t = next_conversion (t)) 10008 { 10009 if (t->kind == ck_user 10010 || t->kind == ck_ambig 10011 || t->kind == ck_identity) 10012 return t->type; 10013 } 10014 gcc_unreachable (); 10015 } 10016 10017 /* Note a warning about preferring WINNER to LOSER. We do this by storing 10018 a pointer to LOSER and re-running joust to produce the warning if WINNER 10019 is actually used. */ 10020 10021 static void 10022 add_warning (struct z_candidate *winner, struct z_candidate *loser) 10023 { 10024 candidate_warning *cw = (candidate_warning *) 10025 conversion_obstack_alloc (sizeof (candidate_warning)); 10026 cw->loser = loser; 10027 cw->next = winner->warnings; 10028 winner->warnings = cw; 10029 } 10030 10031 /* Compare two candidates for overloading as described in 10032 [over.match.best]. Return values: 10033 10034 1: cand1 is better than cand2 10035 -1: cand2 is better than cand1 10036 0: cand1 and cand2 are indistinguishable */ 10037 10038 static int 10039 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn, 10040 tsubst_flags_t complain) 10041 { 10042 int winner = 0; 10043 int off1 = 0, off2 = 0; 10044 size_t i; 10045 size_t len; 10046 10047 /* Candidates that involve bad conversions are always worse than those 10048 that don't. */ 10049 if (cand1->viable > cand2->viable) 10050 return 1; 10051 if (cand1->viable < cand2->viable) 10052 return -1; 10053 10054 /* If we have two pseudo-candidates for conversions to the same type, 10055 or two candidates for the same function, arbitrarily pick one. */ 10056 if (cand1->fn == cand2->fn 10057 && (IS_TYPE_OR_DECL_P (cand1->fn))) 10058 return 1; 10059 10060 /* Prefer a non-deleted function over an implicitly deleted move 10061 constructor or assignment operator. This differs slightly from the 10062 wording for issue 1402 (which says the move op is ignored by overload 10063 resolution), but this way produces better error messages. */ 10064 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 10065 && TREE_CODE (cand2->fn) == FUNCTION_DECL 10066 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn)) 10067 { 10068 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn) 10069 && move_fn_p (cand1->fn)) 10070 return -1; 10071 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn) 10072 && move_fn_p (cand2->fn)) 10073 return 1; 10074 } 10075 10076 /* a viable function F1 10077 is defined to be a better function than another viable function F2 if 10078 for all arguments i, ICSi(F1) is not a worse conversion sequence than 10079 ICSi(F2), and then */ 10080 10081 /* for some argument j, ICSj(F1) is a better conversion sequence than 10082 ICSj(F2) */ 10083 10084 /* For comparing static and non-static member functions, we ignore 10085 the implicit object parameter of the non-static function. The 10086 standard says to pretend that the static function has an object 10087 parm, but that won't work with operator overloading. */ 10088 len = cand1->num_convs; 10089 if (len != cand2->num_convs) 10090 { 10091 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn); 10092 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn); 10093 10094 if (DECL_CONSTRUCTOR_P (cand1->fn) 10095 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn)) 10096 /* We're comparing a near-match list constructor and a near-match 10097 non-list constructor. Just treat them as unordered. */ 10098 return 0; 10099 10100 gcc_assert (static_1 != static_2); 10101 10102 if (static_1) 10103 off2 = 1; 10104 else 10105 { 10106 off1 = 1; 10107 --len; 10108 } 10109 } 10110 10111 for (i = 0; i < len; ++i) 10112 { 10113 conversion *t1 = cand1->convs[i + off1]; 10114 conversion *t2 = cand2->convs[i + off2]; 10115 int comp = compare_ics (t1, t2); 10116 10117 if (comp != 0) 10118 { 10119 if ((complain & tf_warning) 10120 && warn_sign_promo 10121 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2) 10122 == cr_std + cr_promotion) 10123 && t1->kind == ck_std 10124 && t2->kind == ck_std 10125 && TREE_CODE (t1->type) == INTEGER_TYPE 10126 && TREE_CODE (t2->type) == INTEGER_TYPE 10127 && (TYPE_PRECISION (t1->type) 10128 == TYPE_PRECISION (t2->type)) 10129 && (TYPE_UNSIGNED (next_conversion (t1)->type) 10130 || (TREE_CODE (next_conversion (t1)->type) 10131 == ENUMERAL_TYPE))) 10132 { 10133 tree type = next_conversion (t1)->type; 10134 tree type1, type2; 10135 struct z_candidate *w, *l; 10136 if (comp > 0) 10137 type1 = t1->type, type2 = t2->type, 10138 w = cand1, l = cand2; 10139 else 10140 type1 = t2->type, type2 = t1->type, 10141 w = cand2, l = cand1; 10142 10143 if (warn) 10144 { 10145 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT", 10146 type, type1, type2); 10147 warning (OPT_Wsign_promo, " in call to %qD", w->fn); 10148 } 10149 else 10150 add_warning (w, l); 10151 } 10152 10153 if (winner && comp != winner) 10154 { 10155 winner = 0; 10156 goto tweak; 10157 } 10158 winner = comp; 10159 } 10160 } 10161 10162 /* warn about confusing overload resolution for user-defined conversions, 10163 either between a constructor and a conversion op, or between two 10164 conversion ops. */ 10165 if ((complain & tf_warning) 10166 && winner && warn_conversion && cand1->second_conv 10167 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn)) 10168 && winner != compare_ics (cand1->second_conv, cand2->second_conv)) 10169 { 10170 struct z_candidate *w, *l; 10171 bool give_warning = false; 10172 10173 if (winner == 1) 10174 w = cand1, l = cand2; 10175 else 10176 w = cand2, l = cand1; 10177 10178 /* We don't want to complain about `X::operator T1 ()' 10179 beating `X::operator T2 () const', when T2 is a no less 10180 cv-qualified version of T1. */ 10181 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn) 10182 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn)) 10183 { 10184 tree t = TREE_TYPE (TREE_TYPE (l->fn)); 10185 tree f = TREE_TYPE (TREE_TYPE (w->fn)); 10186 10187 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t)) 10188 { 10189 t = TREE_TYPE (t); 10190 f = TREE_TYPE (f); 10191 } 10192 if (!comp_ptr_ttypes (t, f)) 10193 give_warning = true; 10194 } 10195 else 10196 give_warning = true; 10197 10198 if (!give_warning) 10199 /*NOP*/; 10200 else if (warn) 10201 { 10202 tree source = source_type (w->convs[0]); 10203 if (POINTER_TYPE_P (source)) 10204 source = TREE_TYPE (source); 10205 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn) 10206 && warning (OPT_Wconversion, " for conversion from %qH to %qI", 10207 source, w->second_conv->type)) 10208 { 10209 inform (input_location, " because conversion sequence for the argument is better"); 10210 } 10211 } 10212 else 10213 add_warning (w, l); 10214 } 10215 10216 if (winner) 10217 return winner; 10218 10219 /* DR 495 moved this tiebreaker above the template ones. */ 10220 /* or, if not that, 10221 the context is an initialization by user-defined conversion (see 10222 _dcl.init_ and _over.match.user_) and the standard conversion 10223 sequence from the return type of F1 to the destination type (i.e., 10224 the type of the entity being initialized) is a better conversion 10225 sequence than the standard conversion sequence from the return type 10226 of F2 to the destination type. */ 10227 10228 if (cand1->second_conv) 10229 { 10230 winner = compare_ics (cand1->second_conv, cand2->second_conv); 10231 if (winner) 10232 return winner; 10233 } 10234 10235 /* or, if not that, 10236 F1 is a non-template function and F2 is a template function 10237 specialization. */ 10238 10239 if (!cand1->template_decl && cand2->template_decl) 10240 return 1; 10241 else if (cand1->template_decl && !cand2->template_decl) 10242 return -1; 10243 10244 /* or, if not that, 10245 F1 and F2 are template functions and the function template for F1 is 10246 more specialized than the template for F2 according to the partial 10247 ordering rules. */ 10248 10249 if (cand1->template_decl && cand2->template_decl) 10250 { 10251 winner = more_specialized_fn 10252 (TI_TEMPLATE (cand1->template_decl), 10253 TI_TEMPLATE (cand2->template_decl), 10254 /* [temp.func.order]: The presence of unused ellipsis and default 10255 arguments has no effect on the partial ordering of function 10256 templates. add_function_candidate() will not have 10257 counted the "this" argument for constructors. */ 10258 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn)); 10259 if (winner) 10260 return winner; 10261 } 10262 10263 // C++ Concepts 10264 // or, if not that, F1 is more constrained than F2. 10265 if (flag_concepts && DECL_P (cand1->fn) && DECL_P (cand2->fn)) 10266 { 10267 winner = more_constrained (cand1->fn, cand2->fn); 10268 if (winner) 10269 return winner; 10270 } 10271 10272 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */ 10273 if (deduction_guide_p (cand1->fn)) 10274 { 10275 gcc_assert (deduction_guide_p (cand2->fn)); 10276 /* We distinguish between candidates from an explicit deduction guide and 10277 candidates built from a constructor based on DECL_ARTIFICIAL. */ 10278 int art1 = DECL_ARTIFICIAL (cand1->fn); 10279 int art2 = DECL_ARTIFICIAL (cand2->fn); 10280 if (art1 != art2) 10281 return art2 - art1; 10282 10283 if (art1) 10284 { 10285 /* Prefer the special copy guide over a declared copy/move 10286 constructor. */ 10287 if (copy_guide_p (cand1->fn)) 10288 return 1; 10289 if (copy_guide_p (cand2->fn)) 10290 return -1; 10291 10292 /* Prefer a candidate generated from a non-template constructor. */ 10293 int tg1 = template_guide_p (cand1->fn); 10294 int tg2 = template_guide_p (cand2->fn); 10295 if (tg1 != tg2) 10296 return tg2 - tg1; 10297 } 10298 } 10299 10300 /* F1 is a member of a class D, F2 is a member of a base class B of D, and 10301 for all arguments the corresponding parameters of F1 and F2 have the same 10302 type (CWG 2273/2277). */ 10303 if (DECL_P (cand1->fn) && DECL_CLASS_SCOPE_P (cand1->fn) 10304 && !DECL_CONV_FN_P (cand1->fn) 10305 && DECL_P (cand2->fn) && DECL_CLASS_SCOPE_P (cand2->fn) 10306 && !DECL_CONV_FN_P (cand2->fn)) 10307 { 10308 tree base1 = DECL_CONTEXT (strip_inheriting_ctors (cand1->fn)); 10309 tree base2 = DECL_CONTEXT (strip_inheriting_ctors (cand2->fn)); 10310 10311 bool used1 = false; 10312 bool used2 = false; 10313 if (base1 == base2) 10314 /* No difference. */; 10315 else if (DERIVED_FROM_P (base1, base2)) 10316 used1 = true; 10317 else if (DERIVED_FROM_P (base2, base1)) 10318 used2 = true; 10319 10320 if (int diff = used2 - used1) 10321 { 10322 for (i = 0; i < len; ++i) 10323 { 10324 conversion *t1 = cand1->convs[i + off1]; 10325 conversion *t2 = cand2->convs[i + off2]; 10326 if (!same_type_p (t1->type, t2->type)) 10327 break; 10328 } 10329 if (i == len) 10330 return diff; 10331 } 10332 } 10333 10334 /* Check whether we can discard a builtin candidate, either because we 10335 have two identical ones or matching builtin and non-builtin candidates. 10336 10337 (Pedantically in the latter case the builtin which matched the user 10338 function should not be added to the overload set, but we spot it here. 10339 10340 [over.match.oper] 10341 ... the builtin candidates include ... 10342 - do not have the same parameter type list as any non-template 10343 non-member candidate. */ 10344 10345 if (identifier_p (cand1->fn) || identifier_p (cand2->fn)) 10346 { 10347 for (i = 0; i < len; ++i) 10348 if (!same_type_p (cand1->convs[i]->type, 10349 cand2->convs[i]->type)) 10350 break; 10351 if (i == cand1->num_convs) 10352 { 10353 if (cand1->fn == cand2->fn) 10354 /* Two built-in candidates; arbitrarily pick one. */ 10355 return 1; 10356 else if (identifier_p (cand1->fn)) 10357 /* cand1 is built-in; prefer cand2. */ 10358 return -1; 10359 else 10360 /* cand2 is built-in; prefer cand1. */ 10361 return 1; 10362 } 10363 } 10364 10365 /* For candidates of a multi-versioned function, make the version with 10366 the highest priority win. This version will be checked for dispatching 10367 first. If this version can be inlined into the caller, the front-end 10368 will simply make a direct call to this function. */ 10369 10370 if (TREE_CODE (cand1->fn) == FUNCTION_DECL 10371 && DECL_FUNCTION_VERSIONED (cand1->fn) 10372 && TREE_CODE (cand2->fn) == FUNCTION_DECL 10373 && DECL_FUNCTION_VERSIONED (cand2->fn)) 10374 { 10375 tree f1 = TREE_TYPE (cand1->fn); 10376 tree f2 = TREE_TYPE (cand2->fn); 10377 tree p1 = TYPE_ARG_TYPES (f1); 10378 tree p2 = TYPE_ARG_TYPES (f2); 10379 10380 /* Check if cand1->fn and cand2->fn are versions of the same function. It 10381 is possible that cand1->fn and cand2->fn are function versions but of 10382 different functions. Check types to see if they are versions of the same 10383 function. */ 10384 if (compparms (p1, p2) 10385 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2))) 10386 { 10387 /* Always make the version with the higher priority, more 10388 specialized, win. */ 10389 gcc_assert (targetm.compare_version_priority); 10390 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0) 10391 return 1; 10392 else 10393 return -1; 10394 } 10395 } 10396 10397 /* If the two function declarations represent the same function (this can 10398 happen with declarations in multiple scopes and arg-dependent lookup), 10399 arbitrarily choose one. But first make sure the default args we're 10400 using match. */ 10401 if (DECL_P (cand1->fn) && DECL_P (cand2->fn) 10402 && equal_functions (cand1->fn, cand2->fn)) 10403 { 10404 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn)); 10405 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn)); 10406 10407 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn)); 10408 10409 for (i = 0; i < len; ++i) 10410 { 10411 /* Don't crash if the fn is variadic. */ 10412 if (!parms1) 10413 break; 10414 parms1 = TREE_CHAIN (parms1); 10415 parms2 = TREE_CHAIN (parms2); 10416 } 10417 10418 if (off1) 10419 parms1 = TREE_CHAIN (parms1); 10420 else if (off2) 10421 parms2 = TREE_CHAIN (parms2); 10422 10423 for (; parms1; ++i) 10424 { 10425 if (!cp_tree_equal (TREE_PURPOSE (parms1), 10426 TREE_PURPOSE (parms2))) 10427 { 10428 if (warn) 10429 { 10430 if (complain & tf_error) 10431 { 10432 if (permerror (input_location, 10433 "default argument mismatch in " 10434 "overload resolution")) 10435 { 10436 inform (DECL_SOURCE_LOCATION (cand1->fn), 10437 " candidate 1: %q#F", cand1->fn); 10438 inform (DECL_SOURCE_LOCATION (cand2->fn), 10439 " candidate 2: %q#F", cand2->fn); 10440 } 10441 } 10442 else 10443 return 0; 10444 } 10445 else 10446 add_warning (cand1, cand2); 10447 break; 10448 } 10449 parms1 = TREE_CHAIN (parms1); 10450 parms2 = TREE_CHAIN (parms2); 10451 } 10452 10453 return 1; 10454 } 10455 10456 tweak: 10457 10458 /* Extension: If the worst conversion for one candidate is worse than the 10459 worst conversion for the other, take the first. */ 10460 if (!pedantic && (complain & tf_warning_or_error)) 10461 { 10462 conversion_rank rank1 = cr_identity, rank2 = cr_identity; 10463 struct z_candidate *w = 0, *l = 0; 10464 10465 for (i = 0; i < len; ++i) 10466 { 10467 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1) 10468 rank1 = CONVERSION_RANK (cand1->convs[i+off1]); 10469 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2) 10470 rank2 = CONVERSION_RANK (cand2->convs[i + off2]); 10471 } 10472 if (rank1 < rank2) 10473 winner = 1, w = cand1, l = cand2; 10474 if (rank1 > rank2) 10475 winner = -1, w = cand2, l = cand1; 10476 if (winner) 10477 { 10478 /* Don't choose a deleted function over ambiguity. */ 10479 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn)) 10480 return 0; 10481 if (warn) 10482 { 10483 pedwarn (input_location, 0, 10484 "ISO C++ says that these are ambiguous, even " 10485 "though the worst conversion for the first is better than " 10486 "the worst conversion for the second:"); 10487 print_z_candidate (input_location, _("candidate 1:"), w); 10488 print_z_candidate (input_location, _("candidate 2:"), l); 10489 } 10490 else 10491 add_warning (w, l); 10492 return winner; 10493 } 10494 } 10495 10496 gcc_assert (!winner); 10497 return 0; 10498 } 10499 10500 /* Given a list of candidates for overloading, find the best one, if any. 10501 This algorithm has a worst case of O(2n) (winner is last), and a best 10502 case of O(n/2) (totally ambiguous); much better than a sorting 10503 algorithm. */ 10504 10505 static struct z_candidate * 10506 tourney (struct z_candidate *candidates, tsubst_flags_t complain) 10507 { 10508 struct z_candidate *champ = candidates, *challenger; 10509 int fate; 10510 int champ_compared_to_predecessor = 0; 10511 10512 /* Walk through the list once, comparing each current champ to the next 10513 candidate, knocking out a candidate or two with each comparison. */ 10514 10515 for (challenger = champ->next; challenger; ) 10516 { 10517 fate = joust (champ, challenger, 0, complain); 10518 if (fate == 1) 10519 challenger = challenger->next; 10520 else 10521 { 10522 if (fate == 0) 10523 { 10524 champ = challenger->next; 10525 if (champ == 0) 10526 return NULL; 10527 champ_compared_to_predecessor = 0; 10528 } 10529 else 10530 { 10531 champ = challenger; 10532 champ_compared_to_predecessor = 1; 10533 } 10534 10535 challenger = champ->next; 10536 } 10537 } 10538 10539 /* Make sure the champ is better than all the candidates it hasn't yet 10540 been compared to. */ 10541 10542 for (challenger = candidates; 10543 challenger != champ 10544 && !(champ_compared_to_predecessor && challenger->next == champ); 10545 challenger = challenger->next) 10546 { 10547 fate = joust (champ, challenger, 0, complain); 10548 if (fate != 1) 10549 return NULL; 10550 } 10551 10552 return champ; 10553 } 10554 10555 /* Returns nonzero if things of type FROM can be converted to TO. */ 10556 10557 bool 10558 can_convert (tree to, tree from, tsubst_flags_t complain) 10559 { 10560 tree arg = NULL_TREE; 10561 /* implicit_conversion only considers user-defined conversions 10562 if it has an expression for the call argument list. */ 10563 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to)) 10564 arg = build1 (CAST_EXPR, from, NULL_TREE); 10565 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain); 10566 } 10567 10568 /* Returns nonzero if things of type FROM can be converted to TO with a 10569 standard conversion. */ 10570 10571 bool 10572 can_convert_standard (tree to, tree from, tsubst_flags_t complain) 10573 { 10574 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain); 10575 } 10576 10577 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */ 10578 10579 bool 10580 can_convert_arg (tree to, tree from, tree arg, int flags, 10581 tsubst_flags_t complain) 10582 { 10583 conversion *t; 10584 void *p; 10585 bool ok_p; 10586 10587 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10588 p = conversion_obstack_alloc (0); 10589 /* We want to discard any access checks done for this test, 10590 as we might not be in the appropriate access context and 10591 we'll do the check again when we actually perform the 10592 conversion. */ 10593 push_deferring_access_checks (dk_deferred); 10594 10595 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 10596 flags, complain); 10597 ok_p = (t && !t->bad_p); 10598 10599 /* Discard the access checks now. */ 10600 pop_deferring_access_checks (); 10601 /* Free all the conversions we allocated. */ 10602 obstack_free (&conversion_obstack, p); 10603 10604 return ok_p; 10605 } 10606 10607 /* Like can_convert_arg, but allows dubious conversions as well. */ 10608 10609 bool 10610 can_convert_arg_bad (tree to, tree from, tree arg, int flags, 10611 tsubst_flags_t complain) 10612 { 10613 conversion *t; 10614 void *p; 10615 10616 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10617 p = conversion_obstack_alloc (0); 10618 /* Try to perform the conversion. */ 10619 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false, 10620 flags, complain); 10621 /* Free all the conversions we allocated. */ 10622 obstack_free (&conversion_obstack, p); 10623 10624 return t != NULL; 10625 } 10626 10627 /* Convert EXPR to TYPE. Return the converted expression. 10628 10629 Note that we allow bad conversions here because by the time we get to 10630 this point we are committed to doing the conversion. If we end up 10631 doing a bad conversion, convert_like will complain. */ 10632 10633 tree 10634 perform_implicit_conversion_flags (tree type, tree expr, 10635 tsubst_flags_t complain, int flags) 10636 { 10637 conversion *conv; 10638 void *p; 10639 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 10640 10641 if (TREE_CODE (type) == REFERENCE_TYPE) 10642 expr = mark_lvalue_use (expr); 10643 else 10644 expr = mark_rvalue_use (expr); 10645 10646 if (error_operand_p (expr)) 10647 return error_mark_node; 10648 10649 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10650 p = conversion_obstack_alloc (0); 10651 10652 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 10653 /*c_cast_p=*/false, 10654 flags, complain); 10655 10656 if (!conv) 10657 { 10658 if (complain & tf_error) 10659 { 10660 /* If expr has unknown type, then it is an overloaded function. 10661 Call instantiate_type to get good error messages. */ 10662 if (TREE_TYPE (expr) == unknown_type_node) 10663 instantiate_type (type, expr, complain); 10664 else if (invalid_nonstatic_memfn_p (loc, expr, complain)) 10665 /* We gave an error. */; 10666 else 10667 error_at (loc, "could not convert %qE from %qH to %qI", expr, 10668 TREE_TYPE (expr), type); 10669 } 10670 expr = error_mark_node; 10671 } 10672 else if (processing_template_decl && conv->kind != ck_identity) 10673 { 10674 /* In a template, we are only concerned about determining the 10675 type of non-dependent expressions, so we do not have to 10676 perform the actual conversion. But for initializers, we 10677 need to be able to perform it at instantiation 10678 (or instantiate_non_dependent_expr) time. */ 10679 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 10680 if (!(flags & LOOKUP_ONLYCONVERTING)) 10681 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 10682 } 10683 else 10684 expr = convert_like (conv, expr, complain); 10685 10686 /* Free all the conversions we allocated. */ 10687 obstack_free (&conversion_obstack, p); 10688 10689 return expr; 10690 } 10691 10692 tree 10693 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain) 10694 { 10695 return perform_implicit_conversion_flags (type, expr, complain, 10696 LOOKUP_IMPLICIT); 10697 } 10698 10699 /* Convert EXPR to TYPE (as a direct-initialization) if that is 10700 permitted. If the conversion is valid, the converted expression is 10701 returned. Otherwise, NULL_TREE is returned, except in the case 10702 that TYPE is a class type; in that case, an error is issued. If 10703 C_CAST_P is true, then this direct-initialization is taking 10704 place as part of a static_cast being attempted as part of a C-style 10705 cast. */ 10706 10707 tree 10708 perform_direct_initialization_if_possible (tree type, 10709 tree expr, 10710 bool c_cast_p, 10711 tsubst_flags_t complain) 10712 { 10713 conversion *conv; 10714 void *p; 10715 10716 if (type == error_mark_node || error_operand_p (expr)) 10717 return error_mark_node; 10718 /* [dcl.init] 10719 10720 If the destination type is a (possibly cv-qualified) class type: 10721 10722 -- If the initialization is direct-initialization ..., 10723 constructors are considered. ... If no constructor applies, or 10724 the overload resolution is ambiguous, the initialization is 10725 ill-formed. */ 10726 if (CLASS_TYPE_P (type)) 10727 { 10728 vec<tree, va_gc> *args = make_tree_vector_single (expr); 10729 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier, 10730 &args, type, LOOKUP_NORMAL, complain); 10731 release_tree_vector (args); 10732 return build_cplus_new (type, expr, complain); 10733 } 10734 10735 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10736 p = conversion_obstack_alloc (0); 10737 10738 conv = implicit_conversion (type, TREE_TYPE (expr), expr, 10739 c_cast_p, 10740 LOOKUP_NORMAL, complain); 10741 if (!conv || conv->bad_p) 10742 expr = NULL_TREE; 10743 else if (processing_template_decl && conv->kind != ck_identity) 10744 { 10745 /* In a template, we are only concerned about determining the 10746 type of non-dependent expressions, so we do not have to 10747 perform the actual conversion. But for initializers, we 10748 need to be able to perform it at instantiation 10749 (or instantiate_non_dependent_expr) time. */ 10750 expr = build1 (IMPLICIT_CONV_EXPR, type, expr); 10751 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true; 10752 } 10753 else 10754 expr = convert_like_real (conv, expr, NULL_TREE, 0, 10755 /*issue_conversion_warnings=*/false, 10756 c_cast_p, 10757 complain); 10758 10759 /* Free all the conversions we allocated. */ 10760 obstack_free (&conversion_obstack, p); 10761 10762 return expr; 10763 } 10764 10765 /* When initializing a reference that lasts longer than a full-expression, 10766 this special rule applies: 10767 10768 [class.temporary] 10769 10770 The temporary to which the reference is bound or the temporary 10771 that is the complete object to which the reference is bound 10772 persists for the lifetime of the reference. 10773 10774 The temporaries created during the evaluation of the expression 10775 initializing the reference, except the temporary to which the 10776 reference is bound, are destroyed at the end of the 10777 full-expression in which they are created. 10778 10779 In that case, we store the converted expression into a new 10780 VAR_DECL in a new scope. 10781 10782 However, we want to be careful not to create temporaries when 10783 they are not required. For example, given: 10784 10785 struct B {}; 10786 struct D : public B {}; 10787 D f(); 10788 const B& b = f(); 10789 10790 there is no need to copy the return value from "f"; we can just 10791 extend its lifetime. Similarly, given: 10792 10793 struct S {}; 10794 struct T { operator S(); }; 10795 T t; 10796 const S& s = t; 10797 10798 we can extend the lifetime of the return value of the conversion 10799 operator. 10800 10801 The next several functions are involved in this lifetime extension. */ 10802 10803 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The 10804 reference is being bound to a temporary. Create and return a new 10805 VAR_DECL with the indicated TYPE; this variable will store the value to 10806 which the reference is bound. */ 10807 10808 tree 10809 make_temporary_var_for_ref_to_temp (tree decl, tree type) 10810 { 10811 tree var = create_temporary_var (type); 10812 10813 /* Register the variable. */ 10814 if (VAR_P (decl) 10815 && (TREE_STATIC (decl) || CP_DECL_THREAD_LOCAL_P (decl))) 10816 { 10817 /* Namespace-scope or local static; give it a mangled name. */ 10818 /* FIXME share comdat with decl? */ 10819 10820 TREE_STATIC (var) = TREE_STATIC (decl); 10821 CP_DECL_THREAD_LOCAL_P (var) = CP_DECL_THREAD_LOCAL_P (decl); 10822 set_decl_tls_model (var, DECL_TLS_MODEL (decl)); 10823 10824 tree name = mangle_ref_init_variable (decl); 10825 DECL_NAME (var) = name; 10826 SET_DECL_ASSEMBLER_NAME (var, name); 10827 10828 var = pushdecl (var); 10829 } 10830 else 10831 /* Create a new cleanup level if necessary. */ 10832 maybe_push_cleanup_level (type); 10833 10834 return var; 10835 } 10836 10837 /* EXPR is the initializer for a variable DECL of reference or 10838 std::initializer_list type. Create, push and return a new VAR_DECL 10839 for the initializer so that it will live as long as DECL. Any 10840 cleanup for the new variable is returned through CLEANUP, and the 10841 code to initialize the new variable is returned through INITP. */ 10842 10843 static tree 10844 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups, 10845 tree *initp) 10846 { 10847 tree init; 10848 tree type; 10849 tree var; 10850 10851 /* Create the temporary variable. */ 10852 type = TREE_TYPE (expr); 10853 var = make_temporary_var_for_ref_to_temp (decl, type); 10854 layout_decl (var, 0); 10855 /* If the rvalue is the result of a function call it will be 10856 a TARGET_EXPR. If it is some other construct (such as a 10857 member access expression where the underlying object is 10858 itself the result of a function call), turn it into a 10859 TARGET_EXPR here. It is important that EXPR be a 10860 TARGET_EXPR below since otherwise the INIT_EXPR will 10861 attempt to make a bitwise copy of EXPR to initialize 10862 VAR. */ 10863 if (TREE_CODE (expr) != TARGET_EXPR) 10864 expr = get_target_expr (expr); 10865 10866 if (TREE_CODE (decl) == FIELD_DECL 10867 && extra_warnings && !TREE_NO_WARNING (decl)) 10868 { 10869 warning (OPT_Wextra, "a temporary bound to %qD only persists " 10870 "until the constructor exits", decl); 10871 TREE_NO_WARNING (decl) = true; 10872 } 10873 10874 /* Recursively extend temps in this initializer. */ 10875 TARGET_EXPR_INITIAL (expr) 10876 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups); 10877 10878 /* Any reference temp has a non-trivial initializer. */ 10879 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true; 10880 10881 /* If the initializer is constant, put it in DECL_INITIAL so we get 10882 static initialization and use in constant expressions. */ 10883 init = maybe_constant_init (expr); 10884 /* As in store_init_value. */ 10885 init = cp_fully_fold (init); 10886 if (TREE_CONSTANT (init)) 10887 { 10888 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type)) 10889 { 10890 /* 5.19 says that a constant expression can include an 10891 lvalue-rvalue conversion applied to "a glvalue of literal type 10892 that refers to a non-volatile temporary object initialized 10893 with a constant expression". Rather than try to communicate 10894 that this VAR_DECL is a temporary, just mark it constexpr. 10895 10896 Currently this is only useful for initializer_list temporaries, 10897 since reference vars can't appear in constant expressions. */ 10898 DECL_DECLARED_CONSTEXPR_P (var) = true; 10899 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true; 10900 TREE_CONSTANT (var) = true; 10901 } 10902 DECL_INITIAL (var) = init; 10903 init = NULL_TREE; 10904 } 10905 else 10906 /* Create the INIT_EXPR that will initialize the temporary 10907 variable. */ 10908 init = split_nonconstant_init (var, expr); 10909 if (at_function_scope_p ()) 10910 { 10911 add_decl_expr (var); 10912 10913 if (TREE_STATIC (var)) 10914 init = add_stmt_to_compound (init, register_dtor_fn (var)); 10915 else 10916 { 10917 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error); 10918 if (cleanup) 10919 vec_safe_push (*cleanups, cleanup); 10920 } 10921 10922 /* We must be careful to destroy the temporary only 10923 after its initialization has taken place. If the 10924 initialization throws an exception, then the 10925 destructor should not be run. We cannot simply 10926 transform INIT into something like: 10927 10928 (INIT, ({ CLEANUP_STMT; })) 10929 10930 because emit_local_var always treats the 10931 initializer as a full-expression. Thus, the 10932 destructor would run too early; it would run at the 10933 end of initializing the reference variable, rather 10934 than at the end of the block enclosing the 10935 reference variable. 10936 10937 The solution is to pass back a cleanup expression 10938 which the caller is responsible for attaching to 10939 the statement tree. */ 10940 } 10941 else 10942 { 10943 rest_of_decl_compilation (var, /*toplev=*/1, at_eof); 10944 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 10945 { 10946 if (CP_DECL_THREAD_LOCAL_P (var)) 10947 tls_aggregates = tree_cons (NULL_TREE, var, 10948 tls_aggregates); 10949 else 10950 static_aggregates = tree_cons (NULL_TREE, var, 10951 static_aggregates); 10952 } 10953 else 10954 /* Check whether the dtor is callable. */ 10955 cxx_maybe_build_cleanup (var, tf_warning_or_error); 10956 } 10957 /* Avoid -Wunused-variable warning (c++/38958). */ 10958 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type) 10959 && VAR_P (decl)) 10960 TREE_USED (decl) = DECL_READ_P (decl) = true; 10961 10962 *initp = init; 10963 return var; 10964 } 10965 10966 /* Convert EXPR to the indicated reference TYPE, in a way suitable for 10967 initializing a variable of that TYPE. */ 10968 10969 tree 10970 initialize_reference (tree type, tree expr, 10971 int flags, tsubst_flags_t complain) 10972 { 10973 conversion *conv; 10974 void *p; 10975 location_t loc = EXPR_LOC_OR_LOC (expr, input_location); 10976 10977 if (type == error_mark_node || error_operand_p (expr)) 10978 return error_mark_node; 10979 10980 /* Get the high-water mark for the CONVERSION_OBSTACK. */ 10981 p = conversion_obstack_alloc (0); 10982 10983 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false, 10984 flags, complain); 10985 if (!conv || conv->bad_p) 10986 { 10987 if (complain & tf_error) 10988 { 10989 if (conv) 10990 convert_like (conv, expr, complain); 10991 else if (!CP_TYPE_CONST_P (TREE_TYPE (type)) 10992 && !TYPE_REF_IS_RVALUE (type) 10993 && !lvalue_p (expr)) 10994 error_at (loc, "invalid initialization of non-const reference of " 10995 "type %qH from an rvalue of type %qI", 10996 type, TREE_TYPE (expr)); 10997 else 10998 error_at (loc, "invalid initialization of reference of type " 10999 "%qH from expression of type %qI", type, 11000 TREE_TYPE (expr)); 11001 } 11002 return error_mark_node; 11003 } 11004 11005 if (conv->kind == ck_ref_bind) 11006 /* Perform the conversion. */ 11007 expr = convert_like (conv, expr, complain); 11008 else if (conv->kind == ck_ambig) 11009 /* We gave an error in build_user_type_conversion_1. */ 11010 expr = error_mark_node; 11011 else 11012 gcc_unreachable (); 11013 11014 /* Free all the conversions we allocated. */ 11015 obstack_free (&conversion_obstack, p); 11016 11017 return expr; 11018 } 11019 11020 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer, 11021 which is bound either to a reference or a std::initializer_list. */ 11022 11023 static tree 11024 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups) 11025 { 11026 tree sub = init; 11027 tree *p; 11028 STRIP_NOPS (sub); 11029 if (TREE_CODE (sub) == COMPOUND_EXPR) 11030 { 11031 TREE_OPERAND (sub, 1) 11032 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups); 11033 return init; 11034 } 11035 if (TREE_CODE (sub) != ADDR_EXPR) 11036 return init; 11037 /* Deal with binding to a subobject. */ 11038 for (p = &TREE_OPERAND (sub, 0); TREE_CODE (*p) == COMPONENT_REF; ) 11039 p = &TREE_OPERAND (*p, 0); 11040 if (TREE_CODE (*p) == TARGET_EXPR) 11041 { 11042 tree subinit = NULL_TREE; 11043 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit); 11044 recompute_tree_invariant_for_addr_expr (sub); 11045 if (init != sub) 11046 init = fold_convert (TREE_TYPE (init), sub); 11047 if (subinit) 11048 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init); 11049 } 11050 return init; 11051 } 11052 11053 /* INIT is part of the initializer for DECL. If there are any 11054 reference or initializer lists being initialized, extend their 11055 lifetime to match that of DECL. */ 11056 11057 tree 11058 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups) 11059 { 11060 tree type = TREE_TYPE (init); 11061 if (processing_template_decl) 11062 return init; 11063 if (TREE_CODE (type) == REFERENCE_TYPE) 11064 init = extend_ref_init_temps_1 (decl, init, cleanups); 11065 else 11066 { 11067 tree ctor = init; 11068 if (TREE_CODE (ctor) == TARGET_EXPR) 11069 ctor = TARGET_EXPR_INITIAL (ctor); 11070 if (TREE_CODE (ctor) == CONSTRUCTOR) 11071 { 11072 if (is_std_init_list (type)) 11073 { 11074 /* The temporary array underlying a std::initializer_list 11075 is handled like a reference temporary. */ 11076 tree array = CONSTRUCTOR_ELT (ctor, 0)->value; 11077 array = extend_ref_init_temps_1 (decl, array, cleanups); 11078 CONSTRUCTOR_ELT (ctor, 0)->value = array; 11079 } 11080 else 11081 { 11082 unsigned i; 11083 constructor_elt *p; 11084 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor); 11085 FOR_EACH_VEC_SAFE_ELT (elts, i, p) 11086 p->value = extend_ref_init_temps (decl, p->value, cleanups); 11087 } 11088 recompute_constructor_flags (ctor); 11089 if (decl_maybe_constant_var_p (decl) && TREE_CONSTANT (ctor)) 11090 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true; 11091 } 11092 } 11093 11094 return init; 11095 } 11096 11097 /* Returns true iff an initializer for TYPE could contain temporaries that 11098 need to be extended because they are bound to references or 11099 std::initializer_list. */ 11100 11101 bool 11102 type_has_extended_temps (tree type) 11103 { 11104 type = strip_array_types (type); 11105 if (TREE_CODE (type) == REFERENCE_TYPE) 11106 return true; 11107 if (CLASS_TYPE_P (type)) 11108 { 11109 if (is_std_init_list (type)) 11110 return true; 11111 for (tree f = next_initializable_field (TYPE_FIELDS (type)); 11112 f; f = next_initializable_field (DECL_CHAIN (f))) 11113 if (type_has_extended_temps (TREE_TYPE (f))) 11114 return true; 11115 } 11116 return false; 11117 } 11118 11119 /* Returns true iff TYPE is some variant of std::initializer_list. */ 11120 11121 bool 11122 is_std_init_list (tree type) 11123 { 11124 if (!TYPE_P (type)) 11125 return false; 11126 if (cxx_dialect == cxx98) 11127 return false; 11128 /* Look through typedefs. */ 11129 type = TYPE_MAIN_VARIANT (type); 11130 return (CLASS_TYPE_P (type) 11131 && CP_TYPE_CONTEXT (type) == std_node 11132 && init_list_identifier == DECL_NAME (TYPE_NAME (type))); 11133 } 11134 11135 /* Returns true iff DECL is a list constructor: i.e. a constructor which 11136 will accept an argument list of a single std::initializer_list<T>. */ 11137 11138 bool 11139 is_list_ctor (tree decl) 11140 { 11141 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl); 11142 tree arg; 11143 11144 if (!args || args == void_list_node) 11145 return false; 11146 11147 arg = non_reference (TREE_VALUE (args)); 11148 if (!is_std_init_list (arg)) 11149 return false; 11150 11151 args = TREE_CHAIN (args); 11152 11153 if (args && args != void_list_node && !TREE_PURPOSE (args)) 11154 /* There are more non-defaulted parms. */ 11155 return false; 11156 11157 return true; 11158 } 11159 11160 #include "gt-cp-call.h" 11161